late 14c., "that is yet to be; pertaining to a time after the present," from Old French futur "future, to come" (13c.), from Latin futurus "going to be, yet to be," as a noun, "the future," irregular suppletive future participle of esse "to be," from PIE *bheue- (see be). In grammar, of tense, from 1520s.

"future events; time to come," late 14c., modeled on Latin futura, neuter plural of futurus (see future, adj.).