late 14c., mutacioun, "action or process of changing," from Old French mutacion (13c.), and directly from Latin mutationem (nominative mutatio) "a changing, alteration, a turn for the worse," noun of action from past-participle stem of mutare "to change" (from PIE root *mei- (1) "to change, go, move"). The genetics sense "process whereby heritable changes in DNA arise" is from 1894. The linguist's i-mutation is attested from 1874; earlier was i-umlaut (1869), from German, for which mutation was Sweet's English substitute.

late 14c., mewet "silent, not speaking," from Old French muet "dumb, mute" (12c.), diminutive of mut, mo, from Latin mutus "silent, speechless, dumb," probably from imitative base *meue- (source also of Sanskrit mukah "dumb," Greek myein "to be shut," of the mouth). Form assimilated in 16c. to Latin mutus. The meaning "incapable of utterance, dumb" is by mid-15c.

in music, "deaden the sound of," 1861, from mute (n.). Related: Muted; muting.

late 14c. (late 12c. as a surname), "person who does not speak" (from inability, unwillingness, etc.), from mute (adj.). From 1570s as "stage actor in a dumb show." The musical sense "device to deaden the resonance or tone of an instrument" is by 1811 of stringed instruments, 1841 of horns.

by 1840, in reference to musical instruments, past-participle adjective from mute (v.). Figuratively by 1879. Of colors by 1905. Related: mutedness.

"silently, without words or sounds," 1620s, from mute (adj.) + -ly (2).

"dumbness, forbearance from speaking or inability to speak," 1580s, from mute (adj.) + -ness.

1530s, of things (writing or books) "disfigure, maim by depriving of a characteristic part;" 1560s, of persons, "cut off a limb or any important part of;" from Latin mutilatus, past participle of mutilare "to cut off, lop off, cut short; maim, mutilate," from mutilus "maimed," which is of uncertain etymology. Properly, to deprive of some principal part, especially by cutting off, and emphasizing the injury to completeness and beauty. Related: Mutilated; mutilating.

1520s, in Scots law, "act of disabling or wounding a limb," from Middle French mutilation and directly from Late Latin mutilationem (nominative mutilatio), noun of action from past-participle stem of Latin mutilare "to cut or lop off," from mutilus "maimed," which is of uncertain etymology. Of things, "a destroying of unity by damaging or removing a part," from 1630s.