'flashforward' originates from English, specifically the compound of the words 'flash' and 'forward', where 'flash' originally meant 'a sudden burst of light or brief occurrence' and 'forward' meant 'toward the front or toward the future/direction ahead'.

The elements 'flash' (an imitative/late Middle English word for a sudden burst of light or brief event) and 'forward' (from Old English 'forweard', meaning 'toward the front') were combined in modern English usage in the 20th century as the narrative technique term 'flash-forward' (often written with a hyphen or as two words) and later solidified in some contexts as the single word 'flashforward'.

Initially the components described a sudden forward movement or a brief forward-directed occurrence; over time the compound evolved into a technical narrative term meaning 'a short scene that shows events occurring later in a story'.