Impromptu

adv. or a. [Fr. impromptu, from Lat. in promptu, in readiness, at hand, from promptus, visibility, readiness, from promptus, visible, ready. See PROMPT.] Off-hand; without previous study; as, a verse uttered or written impromptu; an impromptu epigram.

n. A piece made off-hand, at the moment, or without previous study; an extemporaneous composition.