Main Entry: ¹when

Pronunciation: \ˈhwen, ˈwen, (h)wən\

Function: adverb

Etymology: Middle English, from Old English hwanne, hwenne; akin to Old High German hwanne when, Old English hwā who — more at who

Date: before 12th century

1 : at what time <when will you return>
2 a : at or during which time b : and then
3 : at a former and usually less prosperous time <brag fondly of having known him when — Vance Packard>