O.E. læt "occurring after the customary or expected time," originally "slow, sluggish," from P.Gmc. *latas (cf. O.N. latr "sluggish, lazy," M.Du., O.S. lat, Ger. laß "idle, weary," Goth. lats "weary, sluggish, lazy," latjan "to hinder"), from PIE base *lad- "slow, weary" (cf. L. lassus "faint, weary, languid, exhausted," Gk. ledein "to be weary"). The sense of "deceased" (as in the late Mrs. Smith) is from late 15c., from an adv. sense of "recently." Of women's menstrual periods, attested colloquially from 1962. Related: Lately; lateness.