Aegis a shield used by Thalia Grace that has a fear-inducing image of Medusa on its front; it turns into a silver bracelet when she isn’t using it
Aethiopian Bull a giant, aggressive African bull whose red hide is impervious to all metal weapons
Agamethus son of King Erginus; half brother of Trophonius, who decapitated him to avoid discovery after their raid on King Hyrieus’s treasury
Amazon a member of a tribe of warrior women
amphitheater an oval or circular open-air space used for performances or sporting events, with spectator seating built in a semicircle around the stage
amphora ceramic jar used to hold wine
Ares the Greek god of war; the son of Zeus and Hera, and half brother to Athena
Artemis the Greek goddess of the hunt and the moon; the daughter of Zeus and Leto, and the twin of Apollo
Asclepius the god of medicine; son of Apollo; his temple was the healing center of ancient Greece
Athena the Greek goddess of wisdom
Athenian of the city of Athens, Greece
Atlas a Titan; father of Calypso and Zoë Nightshade; he was condemned to hold up the sky for eternity after the war between the Titans and the Olympians; he tried unsuccessfully to trick Hercules into taking his place forever, but Hercules tricked him in return
blemmyae a tribe of headless people with faces in their chests
Britomartis the Greek goddess of hunting and fishing nets; her sacred animal is the griffin
Bruttia Crispina a Roman Empress from 178 to 191 CE; she was married to future Roman Emperor Commodus when she was sixteen years old; after ten years of marriage, she was banished to Capri for adultery and later killed
Byzantium an ancient Greek colony that later became Constantinople (now Istanbul)
caduceus the traditional symbol of Hermes, featuring two snakes winding around an often winged staff
Calliope the muse of epic poetry; mother of several sons, including Orpheus
Calypso the goddess nymph of the mythical island of Ogygia; a daughter of the Titan Atlas; she detained the hero Odysseus for many years
Camp Half-Blood the training ground for Greek demigods, located in Long Island, New York
Camp Jupiter the training ground for Roman demigods, located between the Oakland Hills and the Berkeley Hills, in California
Carthaginian Serpent a 120-foot snake that emerged from the River Bagrada in North Africa to confront Roman General Marcus Atilius Regulus and his troops during the First Punic War
Cave of Trophonius a deep chasm, home to the Oracle of Trophonius
centaur a race of creatures that is half-human, half-horse
centicore (see alsoyale) a fierce yak-like creature with large horns that can swivel in any direction
Chiron a centaur; the camp activities director at Camp Half-Blood
chiton a Greek garment; a sleeveless piece of linen or wool secured at the shoulders by brooches and at the waist by a belt
Cloacina goddess of the Roman sewer system
Colosseum an elliptical amphitheater in the center of Rome, Italy, capable of seating fifty thousand spectators; used for gladiatorial contests and public spectacles; also called the Flavian Amphitheater
Colossus Neronis (Colossus of Nero) a gigantic bronze statue of the Emperor Nero; was later transformed into the sun god with the addition of a sunray crown
Commodus Lucius Aurelius Commodus was the son of Roman Emperor Marcus Aurelius; he became co-emperor when he was sixteen and emperor at eighteen, when his father died; he ruled from 177 to 192 CE and was megalomaniacal and corrupt; he considered himself the New Hercules and enjoyed killing animals and fighting gladiators at the Colosseum
Cretan of the island of Crete
Cyclops (Cyclopes, pl.) a member of a primordial race of giants, each with a single eye in the middle of his or her forehead
Daedalus a skilled craftsman who created the Labyrinth on Crete in which the Minotaur (part man, part bull) was kept
daimon Greek for demon; an intermediary spirit between mortals and the gods
Dambe a centuries-old form of boxing associated with the Hausa people of West Africa
Danubian bordering the Danube river in Europe
Daphne a beautiful naiad who attracted Apollo’s attention; she was transformed into a laurel tree in order to escape him
Delos a Greek island in the Aegean Sea near Mykonos; birthplace of Apollo
Demeter the Greek goddess of agriculture; a daughter of the Titans Rhea and Kronos
Demophon the baby son of King Celeus, whom Demeter nursed and tried to make immortal as an act of kindness; brother of Triptolemus
Dionysus the Greek god of wine and revelry; the son of Zeus
Dionysus Festival a celebration held in Athens, Greece, to honor the god Dionysus, the central events of which were theatrical performances
Doors of Death the doorway to the House of Hades, located in Tartarus; doors have two sides—one in the mortal world, and one in the Underworld
elomìíràn the Yoruba word for others
Elysium the paradise to which Greek heroes were sent when the gods gave them immortality
Erythaea an island where the Cumaean Sibyl, a love interest of Apollo, originally lived before he convinced her to leave it by promising her a long life
Eubouleus son of Demeter and Karmanor; the Greek god of swineherds
Fields of Punishment the section of the Underworld where people who were evil during their lives are sent to face eternal punishment for their crimes after death
Flavian the Flavians were an imperial dynasty that ruled the Roman Empire between 69 and 96 CE
Gaea the Greek earth goddess; wife of Ouranos; mother of Titans, giants, Cyclopes, and other monsters
Ganymede a divine hero from Troy whom Zeus abducted to serve as his cupbearer in Olympus
Germani (Germanus, sing.) tribal people who settled to the west of the Rhine river
Gidigbo a form of wrestling that involves head-butting, from the Yoruba of Nigeria, Africa
gloutos Greek for buttocks
Gorgons three monstrous sisters (Stheno, Euryale, and Medusa) who have hair of living, venomous snakes; Medusa’s eyes can turn the beholder to stone
Greek fire an incendiary weapon used in naval battles because it can continue burning in water
griffin a winged creature with the head of an eagle and the body of a lion; the sacred animal of Britomartis
Grove of Dodona the site of the oldest Greek Oracle, second only to Delphi in importance; the rustling of trees in the grove provided answers to priests and priestesses who journeyed to the site
Hades the Greek god of death and riches; ruler of the Underworld
harpy a winged female creature that snatches things
Hausa a language spoken in northern Nigeria and Niger; also the name of a people
Hecate goddess of magic and crossroads
Hemithea teenage daughter of King Staphylus of Naxos; sister of Parthenos; Apollo made her and her sister divine to save them when they jumped off a cliff to escape their father’s rage
Hephaestus the Greek god of fire and crafts and of blacksmiths; the son of Zeus and Hera, and married to Aphrodite
Hera the Greek goddess of marriage; Zeus’s wife and sister; Apollo’s stepmother
Heracles the Greek equivalent of Hercules; the son of Zeus and Alcmene; the strongest of all mortals
Hercules the Roman equivalent of Heracles; the son of Jupiter and Alcmene, who was born with great strength
Hermes Greek god of travelers; guide to spirits of the dead; god of communication
Hessian mercenaries the approximately thirty thousand German troops hired by the British to help fight during the American Revolution when they found it too difficult to recruit their own soldiers
hippocampi (hippocampus, sing.) half-horse, half-fish creatures
Hunters of Artemis a group of maidens loyal to Artemis and gifted with hunting skills and eternal youth as long as they reject romance for life
Hyacinthus a Greek hero and Apollo’s lover, who died while trying to impress Apollo with his discus skills
ichor the golden fluid that is the blood of gods and immortals
ìgboyà the Yoruba word for confidence, boldness, and bravery
Imperial gold a rare metal deadly to monsters, consecrated at the Pantheon; its existence was a closely guarded secret of the emperors
Iris the Greek goddess of the rainbow, and a messenger of the gods
Julius Caesar a Roman politician and general who became a dictator of Rome, turning it from a republic into the Roman Empire
Karmanor a minor Greek harvest god; a local deity in Crete who married Demeter; together they had a son, Eubouleus, who became the god of swineherds
karpoi (karpos, sing.) grain spirits
Kronos the youngest of the twelve Titans; the son of Ouranos and Gaea; the father of Zeus; he killed his father at his mother’s bidding; Titan lord of fate, harvest, justice, and time
Labyrinth an underground maze originally built on the island of Crete by the craftsman Daedalus to hold the Minotaur
Lethe the Greek word for forgetfulness; the name of a river in the Underworld whose waters caused forgetfulness; the name of a Greek spirit of oblivion
Leto mother of Artemis and Apollo with Zeus; goddess of motherhood
Little Tiber the barrier of Camp Jupiter
Lityerses the son of King Midas; he challenged people to harvesting contests and beheaded those he beat, earning him the nickname “Reaper of Men”
Marcus Aurelius Roman Emperor from 161 to 180 CE; father of Commodus; considered the last of the “Five Good Emperors”
Marsyas a satyr who lost to Apollo after challenging him in a musical contest, which led to Marsyas being flayed alive
melomakarona Greek Christmas honey cookies
Midas a king with the power to transform anything he touched to gold; Lityerses’s father; he selected Marsyas as the winner in the musical contest between Apollo and Marsyas, resulting in Apollo giving Midas the ears of a donkey
Minotaur the half-man, half-bull son of King Minos of Crete; the Minotaur was kept in the Labyrinth, where he killed people who were sent in; he was finally defeated by Theseus
Mnemosyne Titan goddess of memory; daughter of Ouranos and Gaea
Mount Olympus home of the Twelve Olympians
Mount Othrys a mountain in central Greece; the Titans’ base during the ten-year war between the Titans and the Olympians
myrmeke a large antlike creature that poisons and paralyzes its prey before eating it; known for protecting various metals, particularly gold
Narcissus a hunter known for his beauty; the son of the river god Cephissus and the nymph Liriope; he was vain, arrogant, and disdainful of admirers; he fell in love with his own reflection; Narcissus was also the name of Commodus’s personal trainer and wrestling partner, who drowned the emperor in his bathtub—these were two different Narcissuses
Nemean Lion a large, vicious lion that plagued Nemea in Greece; its pelt was impervious to all human weapons; Hercules strangled it with his bare hands
Nero ruled as Roman Emperor from 54 to 58 CE; he had his mother and his first wife put to death; many believe he was responsible for setting a fire that gutted Rome, but he blamed the Christians, whom he burned on crosses; he built an extravagant new palace on the cleared land and lost support when construction expenses forced him to raise taxes; he committed suicide
Nine Muses Greek goddesses of literature, science, and the arts, who have inspired artists and writers for centuries
nymph a female nature deity who animates nature
Oceanus the eldest son of Ouranos and Gaea; the Titan god of the sea
Ogygia the island home—and prison—of the nymph Calypso
Oracle of Delphi a speaker of the prophecies of Apollo
Oracle of Trophonius a Greek who was transformed into an Oracle after his death; located at the Cave of Trophonius; known for terrifying those who seek him
Orion a giant huntsman who was the most loyal and valued of Artemis’s attendants until he was slain by a scorpion
Ouranos the Greek personification of the sky; husband of Gaea; father of the Titans
Pan the Greek god of the wild; the son of Hermes
Parthenos teenage daughter of King Staphylus of Naxos; sister of Hemithea; Apollo made her and her sister divine to save them when they jumped off a cliff to escape their father’s rage
Peloponnese a large peninsula and geographic region in southern Greece, separated from the northern part of the country by the Gulf of Corinth
Persephone the Greek queen of the Underworld; wife of Hades; daughter of Zeus and Demeter
podex Latin for anus
Poseidon the Greek god of the sea; son of the Titans Kronos and Rhea, and brother of Zeus and Hades
Potina a Roman goddess of children, who watches over what they are drinking
praetor an elected Roman magistrate and commander of the army
Primordial Chaos the first thing ever to exist; the miasma from which the Fates wove the future; a void from which the first gods were produced
princeps prince of Rome; the early emperors used this title for themselves
Python a monstrous serpent that Gaea appointed to guard the Oracle at Delphi
River Styx the river that forms the boundary between earth and the Underworld
satyr a Greek forest god, part goat and part man
Sibyl a prophetess
Sibylline Books a collection of prophecies in rhyme written in Greek
Sparta a city-state in ancient Greece with military dominance
spatha a long sword used by Roman cavalry units
Staphylus king of Naxos, Greece; a demigod son of Dionysus; father of Hemithea and Parthenos
Styx a powerful water nymph; the eldest daughter of the sea Titan, Oceanus; goddess of the Underworld’s most important river; goddess of hatred; the River Styx is named after her
Suburra an area of the city of Rome that was crowded and lower-class
Tantalus a king who fed the gods a stew made of his own son; he was sent to the Underworld, where his curse was to be stuck in a pool of water under a fruit tree but never be able to drink or eat
Tartarus husband of Gaea; spirit of the abyss; father of the giants; the lowest part of the Underworld
Teumessian Fox a giant fox sent by the gods to ravage the city of Thebes in punishment for a crime; the beast was destined never to be caught
Three Fates Even before there were gods there were the Fates: Clotho, who spins the thread of life; Lachesis, the measurer, who determines how long a life will be; and Atropos, who cuts the thread of life with her shears
Three Mile Island a nuclear power plant near Harrisburg, Pennsylvania, where, on March 28, 1979, there was a partial meltdown in reactor number 2, causing public concern
Throne of Memory Mnemosyne carved this chair, in which a petitioner would sit after visiting the Cave of Trophonius and receiving bits of verse from the Oracle; once seated in the chair, the petitioner would recount the verses, the priests would write them down, and they would become a prophecy
Tiber River the third-longest river in Italy; Rome was founded on its banks; in ancient Rome, executed criminals were thrown into the river
Titan War the epic ten-year battle between the Titans and the Olympians that resulted in the Olympians taking the throne
Titans a race of powerful Greek deities, descendants of Gaea and Ouranos, that ruled during the Golden Age and were overthrown by a race of younger gods, the Olympians
Triptolemus son of King Celeus and brother of Demophon; a favorite of Demeter; he became the inventor of the plow and agriculture
trireme a Greek warship, having three tiers of oars on each side
triumvirate a political alliance formed by three parties
Trojan War According to legend, the Trojan War was waged against the city of Troy by the Achaeans (Greeks) after Paris of Troy took Helen from her husband, Menelaus, king of Sparta
Trophonius demigod son of Apollo, designer of Apollo’s temple at Delphi, and spirit of the dark Oracle; he decapitated his half brother Agamethus to avoid discovery after their raid on King Hyrieus’s treasury
Troy a Roman city situated in modern-day Turkey; site of the Trojan War
Underworld the kingdom of the dead, where souls go for eternity; ruled by Hades
Via Appia the Appian Way, one of the first and most important roads of the ancient Roman republic; after the Roman army subdued the revolt led by Spartacus in 73 BC, they crucified more than six thousand slaves and lined the road for 130 miles with their bodies
yale (see alsocenticore) a fierce yak-like creature with large horns that can swivel in any direction
Yoruba one of the three largest ethnic groups in Nigeria, Africa; also a language and a religion of the Yoruba people
Zeus the Greek god of the sky and the king of the gods
Zoë Nightshade a daughter of Atlas who was exiled and later joined the Hunters of Artemis, becoming the loyal lieutenant of Artemis