1530s, "a running (usually at full speed), a course" (especially of the sun, etc., across the sky), from French carriere "road, racecourse" (16c.), from Old Provençal or Italian carriera, from Vulgar Latin *(via) cararia "carriage (road), track for wheeled vehicles," from Latin carrus "chariot" (see car). Sense of "general course of action or movement" is from 1590s, hence "course of one's public or professional life" (1803).
It forms all or part of: amanuensis; command; commando; commend; countermand; demand; Edmund; emancipate; legerdemain; maintain; manacle; manage; manciple; mandamus; mandate; manege; maneuver; manicure; manifest; manipulation; manner; manque; mansuetude; manual; manubrium; manufacture; manumission; manumit; manure; manuscript; mastiff; Maundy Thursday; mortmain; Raymond; recommend; remand; Sigismund.
It is the hypothetical source of/evidence for its existence is provided by: Hittite maniiahh- "to distribute, entrust;" Greek mane "hand," Latin manus "hand, strength, power over; armed force; handwriting," mandare "to order, commit to one's charge," literally "to give into one's hand;" Old Norse mund "hand," Old English mund "hand, protection, guardian," German Vormund "guardian;" Old Irish muin "protection, patronage."
Proto-Indo-European root meaning "man."
It forms all or part of: alderman; Alemanni; fugleman; Herman; hetman; landsman; leman; man; manikin; mannequin; mannish; mensch; Norman; ombudsman; yeoman.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit manuh, Avestan manu-, Old Church Slavonic mozi, Russian muzh "man, male;" Old English man, mann "human being, person; brave man, hero; servant, vassal."
"a featherless plantigrade biped mammal of the genus Homo" [Century Dictionary], Old English man, mann "human being, person (male or female); brave man, hero;" also "servant, vassal, adult male considered as under the control of another person," from Proto-Germanic *mann- (source also of Old Saxon, Swedish, Dutch, Old High German man, Old Frisian mon, German Mann, Old Norse maðr, Danish mand, Gothic manna "man"), from PIE root *man- (1) "man." For the plural, see men.
Sometimes connected to root *men- (1) "to think," which would make the ground sense of man "one who has intelligence," but not all linguists accept this. Liberman, for instance, writes, "Most probably man 'human being' is a secularized divine name" from Mannus [Tacitus, "Germania," chap. 2], "believed to be the progenitor of the human race."
Specific sense of "adult male of the human race" (distinguished from a woman or boy) is by late Old English (c. 1000); Old English used wer and wif to distinguish the sexes, but wer began to disappear late 13c. and was replaced by man. Universal sense of the word remains in mankind and manslaughter. Similarly, Latin had homo "human being" and vir "adult male human being," but they merged in Vulgar Latin, with homo extended to both senses. A like evolution took place in Slavic languages, and in some of them the word has narrowed to mean "husband." PIE had two other "man" roots: *uiHro "freeman" (source of Sanskrit vira-, Lithuanian vyras, Latin vir, Old Irish fer, Gothic wair; see *wi-ro-) and *hner "man," a title more of honor than *uiHro (source of Sanskrit nar-, Armenian ayr, Welsh ner, Greek anēr; see *ner- (2)).
Man also was in Old English as an indefinite pronoun, "one, people, they." It was used generically for "the human race, mankind" by c. 1200. As a word of familiar address, originally often implying impatience, c.1400; hence probably its use as an interjection of surprise or emphasis, since Middle English but especially popular from early 20c.
As "a woman's lover," by mid-14c. As "adult male possessing manly qualities in an eminent degree," from 14c. Man's man, one whose qualities are appreciated by other men, is by 1873. Colloquial use of the Man for "the boss" is by 1918. To be man or mouse "be brave or be timid" is from 1540s. Meaning "piece with which a game (especially chess) is played" is from c. 1400.
Man-about-town "man of the leisure class who frequents clubs, theaters, and other social resorts" is from 1734. Man of the world is from mid-14c. as "secular man, layman;" by early 15c. as "man experienced in the ways of the world, one able to take things in stride." To do something as one man "unanimously" is from late 14c.
So I am as he that seythe, 'Come hyddr John, my man.' 
MANTRAP, a woman's commodity. [Grose, "Dictionary of the Vulgar Tongue," London, 1785]
At the kinges court, my brother, Ech man for himself. [Chaucer, "Knight's Tale," c. 1386]
Middle English mannen, from Old English mannian "to furnish (a fort, ship, etc.) with a company of men," from man (n.). Meaning "to take up a designated position on a ship" is first recorded 1690s. Meaning "behave like a man, brace up in a manful way, act with courage" is from c. 1400. To man (something) out "play a man's part, bear oneself stoutly and boldly" is from 1660s. Related: Manned; manning.
late 14c., "a soldier;" see man (n.) + war (n.). Meaning "armed ship, vessel equipped for warfare" is from late 15c. Man in the sense of "a ship" is attested from late 15c. in combinations (such as merchantman). The sea creature known as the Portuguese man-of-war (1707) is so called for its sail-like crest. The great U.S. thoroughbred race horse was Man o' War (1917-1947).
"Native North American shaman," by 1801, from adoption of the word medicine in native speech with a sense of "magical influence; something supposed to possess curative, supernatural, or mysterious power." The U.S.-Canadian boundary they called the Medicine Line (attested by 1880), because it conferred a kind of magic protection: punishment for crimes committed on one side of it could be avoided by crossing over to the other. Compare Middle English use of medicine in secondary senses of "moral, psychological, or social remedy; safeguard, defense."
Unless some understanding is arrived at between the American and Canadian Governments that offenders may be promptly and vigorously dealt with, I very much fear that killing and stealing will increase to such an extent that the country along the border will be scarcely habitable. When the Indians are made to understand that the mere fact of "hopping" across the line does not exempt them from punishment, there will be a much greater guarantee of their good behaviour. Now they call the boundary the "Medicine line," because no matter what they have done upon one side they feel perfectly secure after having arrived upon the other. [Report of Superintendent L.N.F. Crozier, Dec. 1880, in "North-West Mounted Police Force Commissioner's Report," 1880]
Hence also medicine bag "pouch containing some article supposed to possess curative or magical powers, worn on the person by native North American people" (1802).