"cast-off skins, shells, or other coverings of animals," 1650s, Latin, literally "that which is stripped off," hence "slough, skin," also "clothing, equipment, arms, booty, spoils," from stem of exuere "to doff," from ex "off" (see ex-) + from PIE root *eu- "to dress" (also found in Latin induere "to dress," reduvia "fragment").