late 14c., envolupen, "be involved" (in sin, crime, etc.), from Old French envoleper "envelop, cover; fold up, wrap up" (10c., Modern French envelopper), from en- "in" (see en-(1)) + voloper "wrap up," which is of uncertain origin, perhaps Celtic (see Gamillscheg, Diez) or Germanic ("Century Dictionary"). Literal sense is from 1580s. Related: Enveloped; enveloping.