1A small black patch worn on the face as an ornament or to conceal a blemish. Now chiefly historical.
2A natural mark on the face resembling such a patch; a beauty spot.
Late 17th century; earliest use found in Richard Wiseman (bap. 1615, d. 1676), surgeon. From French mouche small piece of taffeta worn on the face, small tuft of hair allowed to grow beneath the lower lip, specific uses of mouche fly from classical Latin musca fly.