1680s, "ear trumpet for the hard-of-hearing," coined from Greek mikros "small" (see micro-) + phōnē "sound," from PIE root *bha- (2) "to speak, tell, say." The notion is "instrument for augmenting small sounds." Modern sense of "transducer that converts sound into an electrical signal" is by 1924 in radio broadcasting and movie recording, from the earlier sense "amplifying telephone transmitter" (1878). Of the two spellings of the short form of the word, mike (1924) is older than mic (1961). Related: Microphonic; microphony.
type of tires, 1902, from French motor vehicle manufacturers André (1853-1931) and Édouard (1859-1940) Michelin, who first made the tires. In reference to the popular touring and gastronomic guides published by the company since 1900, by 1919 in English. The surname is a diminutive of Michel (see Michael).
word-forming element meaning "small in size or extent, microscopic; magnifying;" in science indicating a unit one millionth of the unit it is prefixed to; from Latinized form of mikros, Attic form of Greek smikros "small, little, petty, trivial, slight," perhaps from PIE *smika, from root *smik- "small" (source also of Old High German smahi "littleness"), but Beekes thinks it a Pre-Greek word.
"urinate," by 1835, from micturition; malformed and with an erroneous sense; condemned from its birth.