1560s, with noun suffix -y (1) + obsolete verb mutine "revolt" (1540s), from Middle French mutiner "to revolt," from meutin "rebellious," from meute "a revolt, movement," from Vulgar Latin *movita "a military uprising," from fem. past participle of Latin movere "to move" (see move (v.)).
1580s, from mutiny (n.). Alternative mutine is recorded from 1550s. Related: Mutinied; mutinying.