Camp Half-Blood the training ground for Greek demigods, located in Long Island, New York
Camp Jupiter the training ground for Roman demigods, located in California, between the Oakland Hills and the Berkeley Hills
Celestial bronze a powerful magical metal used to create weapons wielded by Greek gods and their demigod children
centurion an officer in the Roman army
charmspeak a rare type of hypnotism power that chosen children of Aphrodite possess
Cicero a Roman statesman who was renowned for his public speeches
Circus Maximus a stadium designed for horse and chariot racing
cloaca maxima Latin for greatest sewer
clunis Latin for buttocks
cohort groups of legionnaires
Colosseum an elliptical amphitheater built for gladiator fights, monster simulations, and mock naval battles
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
Cumaean Sibyl an Oracle of Apollo from Cumae who collected her prophetic instructions for averting disaster in nine volumes but destroyed six of them when trying to sell them to Tarquinius Superbus of Rome
Cyclops (Cyclopes, pl.) a member of a primordial race of giants, each with a single eye in the middle of his or her forehead
cynocephalus (cynocephali, pl.) a being with a human body and a dog’s head
Dante an Italian poet of the late Middle Ages who invented terza rima; author of The Divine Comedy, among other works
Daphne a beautiful naiad who attracted Apollo’s attention; she transformed into a laurel tree in order to escape him
decimation the ancient Roman punishment for bad legions in which every tenth soldier was killed whether they were guilty or innocent
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. Roman form: Ceres
denarius (denarii, pl.) a unit of Roman currency
Diana the Roman goddess of the hunt and the moon; the daughter of Jupiter and Leto, and the twin of Apollo. Greek form: Artemis
Dionysus Greek god of wine and revelry; the son of Zeus. Roman form: Bacchus
dryad a spirit (usually female) associated with a certain tree
Eagle of the Twelfth the standard of Camp Jupiter, a gold icon of an eagle on top of a pole, symbolizing the god Jupiter
Earthborn a race of six-armed giants, also called Gegenes
Elysium the paradise to which Greek heroes are sent when the gods grant them immortality
Erythraean Sibyl a prophetess who presided over Apollo’s Oracle at Erythrae in Ionia
eurynomos (eurynomoi, pl.) a corpse-eating ghoul that lives in the Underworld and is controlled by Hades; the slightest cut from their claws causes a wasting disease in mortals, and when their victims die, they rise again as vrykolakai, or zombies. If a eurynomos manages to devour the flesh of a corpse down to the bones, the skeleton will become a fierce undead warrior, many of whom serve as Hades’s elite palace guards.
Euterpe the Greek goddess of lyric poetry; one of the Nine Muses; daughter of Zeus and Mnemosyne
fasces a ceremonial ax wrapped in a bundle of thick wooden rods with its crescent-shaped blade projecting outward; the ultimate symbol of authority in ancient Rome; origin of the word fascism
Fates three female personifications of destiny. They control the thread of life for every living thing from birth to death.
faun a Roman forest god, part goat and part man
Faunus the Roman god of the Wild. Greek form: Pan
Field of Mars part battlefield, part party zone, the place where drills and war games are held at Camp Jupiter
First Titan War also known as the Titanomachy, the eleven-year conflict between the Titans from Mount Othrys and the younger gods, whose future home would be Mount Olympus
Forum the center of life in New Rome; a plaza with statues and fountains that is lined with shops and nighttime entertainment venues
fuerte Spanish for strong
fulminata armed with lightning; a Roman legion under Julius Caesar whose emblem was a lightning bolt (fulmen)
Gaea the Greek earth goddess; wife of Ouranos; mother of the Titans, giants, Cyclopes, and other monsters
Gamelion the seventh month of the Attic or Athenian calendar that was used in Attica, Greece, at one time; roughly equivalent to January/February on the Gregorian calendar
Germani bodyguards for the Roman Empire from the Gaulish and Germanic tribes
Greek fire a magical, highly explosive, viscous green liquid used as a weapon; one of the most dangerous substances on earth
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. The grove is located in Camp Half-Blood Forest and accessible only through the myrmekes’ lair.
Hades the Greek god of death and riches; ruler of the Underworld. Roman form: Pluto
Harpocrates the Ptolemaic god of silence and secrets, a Greek adaptation of Harpa-Khruti, Horus the Child, who was often depicted in art and statuary with his finger held up to his lips, a gesture symbolizing childhood
harpy a winged female creature that snatches things
Hecate the goddess of magic and crossroads
Hector a Trojan champion who was ultimately slain by the Greek warrior Achilles and then dragged by the heels behind Achilles’s chariot
Helios the Titan god of the sun; son of the Titan Hyperion and the Titaness Theia
Hephaestus the Greek god of fire, including volcanic, and of crafts and blacksmithing; the son of Zeus and Hera, and married to Aphrodite. Roman form: Vulcan
Hera the Greek goddess of marriage; Zeus’s wife and sister; Apollo’s stepmother. Roman form: Juno
Hermes the Greek god of travelers; guide to spirits of the dead; god of communication. Roman form: Mercury.
hippocampus a sea creature with a horse’s head and a fish’s body
Horatius Cocles a Roman officer who, according to legend, single-handedly defended the Sublician Bridge over the Tiber River from the invading Etruscan army
Hyacinthus a Greek hero and Apollo’s lover, who died while trying to impress Apollo with his discus skills
immortuos Latin for undead
Imperial gold a rare metal deadly to monsters, consecrated at the Pantheon; its existence was a closely guarded secret of the emperors
Iris Greek goddess of the rainbow
jiangshi Chinese for zombie
Julius Caesar a Roman politician and general whose military accomplishments extended Rome’s territory and ultimately led to a civil war that enabled him to assume control of the government in 49 BCE. He was declared “dictator for life” and went on to institute social reforms that angered some powerful Romans. A group of senators conspired against him and assassinated him on March 15, 44 BCE.
Juno the Roman goddess of marriage; Jupiter’s wife and sister; Apollo’s stepmother. Greek form: Hera
Jupiter the Roman god of the sky and king of the gods. Greek form: Zeus
Jupiter Optimus Maximus Latin for Jupiter, the best and greatest god
Khromanda (Khromandae, pl.) a humanoid monster with gray eyes, a shaggy blond pelt, and doglike teeth; it can only communicate in loud shrieks
Koronis daughter of a king; one of Apollo’s girlfriends, who fell in love with another man. A white raven Apollo had left to guard her informed him of the affair. Apollo was so angry at the raven for failing to peck out the man’s eyes that he cursed the bird, scorching its feathers. Apollo sent his sister, Artemis, to kill Koronis, because he couldn’t bring himself to do it.