Words derived from mythology.

Aegis - Protection, sponsorship. The shield or buckler belonging to Zeus, supposedly made by Hephaestus, decorated with golden tassels and containing the head of Medusa in the center. From Greek mythology.

Ambrosia - Something extremely pleasing to taste or smell. A food or drink of the gods from Greek mythology.

Aphrodisiac (Aphrodite) - An agent (as a food or drug) that arouses or is held to arouse sexual desire. From Aphrodite, the Greek goddess of love, lust, beauty, and sexuality.

Atlas - A bound collection of maps often including illustrations, informative tables, or textual matter. From Atlas, one of the primordial Titans in Greek mythology, whose punishment was to hold the sky upon his shoulders.

Aurora - Dawn. From Aurora, the Roman goddess of dawn.

Berserk - Frenzied, crazed. From the Norse Berserkers, who were warriors that fought while in an "uncontrollable rage or trance of fury".

Cereal (Ceres) - Relating to grain or to the plants that produce it. Derived from Ceres, the Roman goddess of agriculture.

Echo - The repetition of a sound caused by reflection of sound waves. A repetition or imitation of another. Perhaps from Greek mythology, a mountain nymph who was punished by Hera to repeat only the last words of other people's sentences. She also fell in love with Narcissus.

Fauna - The animals characteristic of a region, period, or special environment. From the Roman fertility goddess, Fauna, who was also either the wife, sister, or daughter of Faunus.

Flora - Plant or bacterial life. From Roman mythology, the name of the goddess of flowers and spring.

Friday (Frige) - The fifth or sixth day of the week. Derived from Frige, the love goddess of Norse mythology, and also the wife of Odin.

Hades - Used as a synonym for "hell" by some (not sure if this one should count). The Greek god and personification of the underworld.

Helium (Helios) - A light colorless inert gaseous element found especially in natural gases and used chiefly for inflating airships and balloons, in lamps, in cryogenic research, and as a component of inert atmospheres (as in welding). From Helios, the Greek personification of the sun.

Hell - A nether world in which the dead continue to exist. Possibly named after Hel, the queen of the Norse underworld. This is, of course, not certain.

Hermaphrodite (Hermaphroditus) - An animal or plant having both male and female reproductive organs. Something that is a combination of diverse elements. From Greek mythology, a child of Hermes and Aphrodite, who was turned into a hermaphrodite when the nymph Salmacis attempted to rape him [Hermaphroditus] and then called out to the gods requesting that they never part.

Hermetic (Hermes Trismegistus) - Obscure, secret, isolated, airtight. From Greek mythology, Hermes Trismegistus, who was a combination of the Greek Hermes, and the Egyptian Thoth. They were both gods of magic and writing. He was not widely considered to be Hermes, but rather, a separate entity.

January (Janus) - The first month of the Gregorian calendar. Named after Janus, the Roman god of gates, doorways, beginnings, and endings.

Jovial (Jupiter) - Markedly good-humored especially as evidenced by jollity and conviviality. From the chief god of the Roman pantheon, Jupiter.

June (Juno) - The sixth month of the Gregorian calendar. Possibly named after Juno, the queen of the gods in Roman mythology.

Labyrinth -  A place constructed of or full of intricate passageways and blind alleys. A maze. Something extremely complex or tortuous in structure, arrangement, or character. "An elaborate structure constructed for King Minos of Crete and designed by the legendary artificer Daedalus to hold the Minotaur, a creature that was half man and half bull and which was eventually killed by the Athenian hero Theseus."

March (Mars) - The third month of the Gregorian calendar. Named after Mars, the Roman god of war.

Martial (Mars) - Of, relating to, or suited for war or a warrior. Relating to an army or to military life. From Mars, the Roman god of war.

May (Maia) - The fifth month of the Gregorian calendar. Possibly from the Roman goddess Maia, wife of Vulcan.

Mentor - A trusted counselor or guide. Tutor. From Greek mythology, an old man who was the friend of Odysseus.

Mint (Minthe) - Any of a genus (Mentha) of mints that have white, purple, or pink verticillate flowers with a nearly regular corolla and four equal stamens and that include some used in flavoring and cookery. From Greek mythology, a naiad associated with the river Cocytus. She was dazzled by Hades' golden chariot and was about to be seduced by him had not Queen Persephone metamorphosed Minthe into the pungently sweet-smelling mint

Monday (Mani) - The first or second day of the week. Its name is from the Moon, which is derived from the Norse god of the moon, Mani, who would pull the moon through the sky every night while being chased by Hati.

Morphine (Morpheus) - An analgesic and sedative. From Morpheus, the Greek god of dreams.

Museum (Muse) - An institution devoted to the procurement, care, study, and display of objects of lasting interest or value. A place where objects are exhibited. From Greek "mouseion", a place or temple dedicated to the Muses.

Narcissism/Narcissist (Narcissus) - Love of or sexual desire for one's own body. Egoism, egocentrism. From Greek mythology, a beautiful youth who fell in love with his own reflection (how this happened depends on the story, as there a few different versions).

Nemesis - One that inflicts retribution or vengeance. A formidable and usually victorious rival or opponent. From Greek mythology, the goddess of divine retribution.

Ocean (Oceanus) - The whole body of salt water that covers nearly three fourths of the surface of the earth. From Greek mythology, Oceanus was believed to be a large river that encircled the earth. Oceanus was also the personification of this "river".

Odyssey -  A long wandering or voyage usually marked by many changes of fortune. An ancient Greek epic by Homer, mostly starring Odysseus during his journey after the fall of Troy.

Panic (Pan) - A sudden overpowering fright. From Pan, a Greek god who could cause contagious, groundless fear in herds and crowds, or in people in lonely spots.

Priapism (Priapus) - An abnormal often painful persistent erection of the penis. Priapus was a minor fertility deity in Greek mythology who wasn't taken all that seriously.

Rhadamanthine (Rhadamanthus) - Rigorously strict or just. From Rhadamanthus, who was one of the judges of the underworld in Greek mythology, and said to be wise as well as just.

Saturday (Saturn) - The sixth or seventh day of the week. From Saturn, a Roman agriculture and harvest deity.

Siren - A woman who sings with enchanting sweetness. A device often electrically operated for producing a penetrating warning sound. From the Greek sea nymph Siren, whose singing would lure sailors to their destruction.

Thursday (Thor) - The fourth or fifth day of the week. Derived from Thor, the Norse god of thunder, as well as the son of Odin and Jord.

Titanic (Titan) - Having great magnitude, force, or power. From the Titans of Greek mythology.

Tuesday (Tyr) - The second or third day of the week. Derived from Tyr, the Norse god of war.

Vestal (Vesta) - Chaste. From the Roman virgin goddess Vesta, who was the goddess of home, hearth, and family.

Volcano (Vulcan) - A vent in the crust of the earth or another planet or a moon from which usually molten or hot rock and steam issue. From the Roman god of fire, Vulcan.

Wednesday (Odin) - The third or fourth day of the week. Derived from the head God of the Norse pantheon, Odin.

Zephyr (Zephyrus) - A breeze from the west, or a gentle breeze. The Greek god of the west wind, who was the most gentle of the winds.

Most of the definitions are from Merriam-Webster, and mythology research was mostly from Wikipedia. Hopefully, there's no factual errors (or any other kind of errors, for that matter).