redundant (adj.)

1590s, from Latin redundantem (nominative redundans), present participle of redundare, literally "overflow, pour over; be over-full;" figuratively "be in excess," from re- "again" (see re-) + undare "rise in waves," from unda "a wave," from PIE *unda-, nasalized form of root *wed- (1) "water; wet." Of persons, in employment situations, from 1928, chiefly British. Related: Redundantly.