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" (see water (n.1)). Of persons, in employment situations, from 1928, chiefly British. Related: Redundantly.