Entries linking to instantly
mid-15c., "now, present, of the moment, current," from Old French instant "near, imminent, immediate, at hand; urgent, assiduous" (14c.) and directly from Medieval Latin instantem (nominative instans), in classical Latin "present, pressing, urgent," literally "standing near," present participle of instare "to urge, to stand near, be present (to urge one's case)," from in- "in" (from PIE root *en "in") + stare "to stand," from PIE root *sta- "to stand, make or be firm."
Sense of "immediate, done or occurring at once" is from 1590s. Of processed foods, by 1912; instant coffee is from 1915. Televised sports instant replay attested by 1965. Instant messaging attested by 1994.
common adverbial suffix, forming from adjectives adverbs signifying "in a manner denoted by" the adjective, Middle English, from Old English -lice, from Proto-Germanic *-liko- (cognates: Old Frisian -like, Old Saxon -liko, Dutch -lijk, Old High German -licho, German -lich, Old Norse -liga, Gothic -leiko); see -ly (1). Cognate with lich, and identical with like (adj.).
Weekley notes as "curious" that Germanic uses a word essentially meaning "body" for the adverbial formation, while Romanic uses one meaning "mind" (as in French constamment from Latin constanti mente). The modern English form emerged in late Middle English, probably from influence of Old Norse -liga.