impromptu Look up impromptu at Dictionary.com
1669 (adv.), 1764 (adj.), from Fr. impromptu (1659), from L. in promptu "in readiness," from in "in" + promptu, abl. of promptus "readiness," from pp. of promere "to bring out," from pro- "before, forward, for" + emere "to obtain" (see exempt).