Kronos the Titan lord of time, evil, and the harvest. He is the youngest but boldest and most devious of Gaea’s children; he convinced several of his brothers to aid him in the murder of their father, Ouranos. He was also Percy Jackson’s primary opponent. Roman form: Saturn

Labyrinth an underground maze originally built on the island of Crete by the craftsman Daedalus to hold the Minotaur

lamia Roman term for zombie

Lar (Lares, pl.) Roman house gods

legionnaire a member of the Roman army

Lemurian from the ancient continent of Lemuria, now lost, but once thought to be located in the Indian Ocean

Leto mother of Artemis and Apollo with Zeus; goddess of motherhood

libri Latin for books

lictor an officer who carried a fasces and acted as a bodyguard for Roman officials

Little Tiber named after the Tiber River of Rome, the smaller river that forms the barrier of Camp Jupiter

Luna the moon Titan. Greek form: Selene

Lupa the wolf goddess, guardian spirit of Rome

maenad a female follower of Dionysus/Bacchus, often associated with frenzy

manubalista a Roman heavy crossbow

Mars the Roman god of war. Greek form: Ares

Medea a Greek enchantress, daughter of King Aeëtes of Colchis and granddaughter of the Titan sun god, Helios; wife of the hero Jason, whom she helped obtain the Golden Fleece

Meleager a prince who the Fates predicted would die when a piece of firewood was consumed. When his mother discovered that Meleager had killed her two brothers, she threw the wood into the fire, bringing about his death.

Meliai Greek nymphs of the ash tree, born of Gaea; they nurtured and raised Zeus in Crete

Mercury the Roman god of travelers; guide to spirits of the dead; god of communication. Greek form: Hermes

Minerva the Roman goddess of wisdom. Greek form: Athena

Mist a magical force that prevents mortals from seeing gods, mythical creatures, and supernatural occurrences by replacing them with things the human mind can comprehend

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; the seat of the Titans in Marin County, California; known by mortals as Mount Tamalpais

Mount Vesuvius a volcano near the Bay of Naples in Italy that erupted in the year 79 CE, burying the Roman city of Pompeii under ash

muster a formal assembly of troops

myrmeke a giant antlike creature the size of a full-grown German shepherd. Myrmekes live in enormous anthills, where they store shiny loot, like gold. They spit poison and have nearly invincible body armor and vicious mandibles.

naiad a female water spirit

Nereid a spirit of the sea

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

New Rome both the valley in which Camp Jupiter is located and a city—a smaller, modern version of the imperial city—where Roman demigods can go to live in peace, study, and retire

Nine Muses goddesses who grant inspiration for and protect artistic creation and expression; daughters of Zeus and Mnemosyne; as children, they were taught by Apollo. Their names are: Clio, Euterpe, Thalia, Melpomene, Terpsichore, Erato, Polymnia, Ourania, and Calliope.

nuntius Latin for messenger

nymph a female deity who animates nature

Oliver Cromwell a devout Puritan and influential political figure who led the parliamentary army during the English Civil War

Oracle of Delphi a speaker of the prophecies of Apollo

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. Roman form: Faunus

pandos (pandai, pl.) a man with gigantic ears, eight fingers and toes, and a body covered with hair that starts out white and turns black with age

People’s Park a property located off Telegraph Avenue in Berkeley, California, that was the site of a major confrontation between student protestors and police in May 1969

Phlegethon the River of Fire in the Underworld

Pluto the Roman god of death and ruler of the Underworld. Greek form: Hades

Pomerian Line the border of Rome

Pompeii a Roman city that was destroyed in 79 CE when the volcano Mount Vesuvius erupted and buried it under ash

Poseidon the Greek god of the sea; son of the Titans Kronos and Rhea, and the brother of Zeus and Hades. Roman form: Neptune

praetor an elected Roman magistrate and commander of the army

praetorium the living quarters for the praetors at Camp Jupiter

princeps Latin for first citizen or first in line; the early Roman emperors adopted this title for themselves, and it came to mean prince of Rome

principia the military headquarters for the praetors at Camp Jupiter

probatio the rank assigned to new members of the legion at Camp Jupiter

Ptolemaic relating to the Greco-Egyptian kings who ruled Egypt from 323 to 30 BCE

Python a monstrous dragon that Gaea appointed to guard the Oracle at Delphi

River Styx the river that forms the boundary between Earth and the Underworld

Romulus a demigod son of Mars, twin brother of Remus; first king of Rome, who founded the city in 753 BCE

Saturnalia an ancient Roman festival held in December in honor of the god Saturn, the Roman equivalent of Kronos

satyr a Greek forest god, part goat and part man

Selene the moon Titan. Roman form: Luna

Senate a council of ten representatives elected from the legion at Camp Jupiter

Senate House the building at Camp Jupiter where the senators meet to discuss such issues as whether a quest should be granted or whether war should be declared

Sibyl a prophetess

Sibylline Books the Cumaean Sibyl’s prophecies—prescriptions for warding off disasters—dating back to ancient Roman times, collected in nine volumes, six of which were destroyed by the Sibyl herself. The three remaining books were sold to the last Roman king, Tarquin, and then lost over time. Ella the harpy read a copy of the three Books and is trying to reconstruct all the prophecies with her photographic memory and the help of Tyson the Cyclops.

sica (siccae, pl.) a short, curved sword

Somme a battle of World War I fought by the British and French against the Germans by the River Somme in France

Somnus the Roman god of sleep

spatha a Roman cavalry sword

spolia opima one-on-one combat between two opposing leaders in a war, the ultimate display of courage for a Roman; literally, spoils of war

strix (strixes, pl.) a large blood-drinking owl-like bird of ill omen

Stymphalian birds monstrous man-eating birds with sharp Celestial bronze beaks that can tear through flesh. They can also shoot their feathers at prey like arrows.

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

sub rosa Latin for under the rose, meaning sworn to secrecy

Subura a crowded lower-class area of ancient Rome

Summer of Love a gathering of more than 100,000 hippies or “flower children” in the San Francisco neighborhood of Haight-Ashbury during the summer of 1967 to enjoy art, music, and spiritual practices while also protesting the government and materialistic values