later adj., adv.

Old English læt "occurring after the customary or expected time," originally "slow, sluggish, slack, lax, negligent," from Proto-Germanic *lata- (source also of Old Norse latr "sluggish, lazy," Middle Dutch, Old Saxon lat, Dutch laat, German laß "idle, weary," Gothic lats "weary, sluggish, lazy," latjan "to hinder"), from PIE *led- "slow, weary," from root *‌‌lē- "to let go, slacken."

From mid-13c. as "occurring in the latter part of a period of time." From c. 1400 as "being or occurring in the near, or not too distant, past; recent" (of late). From this comes the early 15c. sense "recently dead, not many years dead" (as in the late Mrs. Smith). Of menstruation, attested colloquially from 1962. Expression better late than never is attested from late 15c. As an adverb, from Old English late "slowly."

Old English lætra "slower," comparative of læt "late" (see late (adj.)). Meaning "belonging to a subsequent period" is from c. 1200. Sense of "that has been mentioned second of two or last" is first recorded 1550s.

In modern use the more common word is later, which is from mid-15c. and is perhaps a new formation or a variant of this word. Latter survives mostly in the phrase the latter, which, with the former is used to avoid repetition (but sometimes incorrectly, when more than two are involved).