c. 1300 as the name of the bright reddish-orange planet in the heavens; late 14c. as the name of the Roman god of war, from Latin Mars (stem *Mawort-), the Roman god of war (identified with Greek Ares), a name of unknown origin, apparently from earlier Mavors, related to Oscan Mamers.

According to Watkins the Latin word is from *Mawort- "name of an Italic deity who became the god of war at Rome ...." He also had agricultural attributes, and might ultimately have been a Spring-Dionysus. The planet was so named by the Romans, no doubt for its blood-like color. The Greeks also called the planet Pyroeis "the fiery." Also in medieval alchemy, "iron" (late 14c.). The Mars candy bar was first manufactured in 1932 by Forrest Mars Sr. of the candy-making family.

masc. proper name, from Latin Martinus, derivative of Mars (genitive Martis), Roman god of war (see Mars). In Elizabethan times, the parish of St. Martin-le-Grand in London was "celebrated as the resort of dealers in imitation jewellery" [OED].

third month of our year, first month of the ancient Roman calendar, c. 1200, from Anglo-French marche, Old French marz, from Latin Martius (mensis) "(month) of Mars," from Mars (genitive Martis). The Latin word also is the source of Spanish marzo, Portuguese março, Italian marzo, German März, Dutch Maart, Danish Marts, etc.

Replaced Old English hreðmonaþ, the first part of which is of uncertain meaning, perhaps from hræd "quick, nimble, ready, active, alert, prompt." Another name for it was Lide, Lyde (c.1300), from Old English hlyda, which is perhaps literally "noisy" and related to hlud "loud" (see loud). This fell from general use 14c. but survived into 19c. in dialect.

For March hare, proverbial type of madness, see mad (adj.). The proverb about coming in like a lion and going out like a lamb is since 1630s. March weather has been figurative of changeableness since mid-15c.

royal palace in Rome, later the Italian presidential palace, 1838, from Mons Quirinalis in Rome (one of the seven hills, site of a former Papal palace), from Quirinus, said to be the divine name of Romulus, but rather one of the original trinity of Roman gods, assimilated to Mars. His feast (Quirinalia) was Feb. 17, the day Romulus was said to have been translated to heaven. Used metonymically for "the Italian civil government" (1917), especially as distinguished from the Vatican.

satellite of Mars, discovered in 1877, named for Greek deimos, literally "fear, terror," also, as Deimos, the personification of such, regarded as a son of Ares, twin brother of Phobos"fear, panic, flight" (for which see phobia). Greek deimos is from PIE *duei- "fear," source also of Sanskrit dvesti "hate," Avestan duuaetha "threat," and possibly Latin dirus "fearful."

kind of white wine, 1806, named for the seaport town on the west coast of Sicily, in the region where it is produced, the name of which is said to be from Arabic Mirsa-llahi, literally "the Port of God."

French national republican song, 1826, from fem. of adjective Marseillais "of Marseilles." The tune originally was "War Song for the Rhine Army," composed (for the Strasbourg volunteers) by royalist officer Capt. Claude Joseph Rouget de Lisle (1760-1836); the current name is because it was sung enthusiastically by soldiers from Marseilles advancing on the Tuileries, Aug. 10, 1792. However, during the Revolution, the city was punished for its royalist Sympathies by being stripped of its name and called instead  Ville-sans-Nom "city without a name" (which is, of course, a name).

surname, from marshal (n.). The city in Texas, U.S., was named in 1841 for U.S. Supreme Court Chief Justice John Marshall (1755-1835). The Marshall Plan, "U.S. assistance to aid certain Western European nations recovering from World War II," is from 1947, named for its initiator, George C. Marshall (1880-1959), who was U.S. Secretary of State 1947-49. The Marshall Islands in the western Pacific were explored in 1788 by British naval captains John Marshall (1748-1819) and Thomas Gilbert, and named for the former (for the latter, see Kiribati). Related: Marshallese.