improvisation Meaning, Definition & Usage

  1. noun a creation spoken or written or composed extemporaneously (without prior preparation)
  2. noun an unplanned expedient
    temporary expedient.
  3. noun a performance given extempore without planning or preparation
    extemporization; extemporisation.

WordNet

Im*prov`i*sa"tion noun
Etymology
Cf. F. improvisation.
Definitions
  1. The act or art of composing and rendering music, poetry, and the like, extemporaneously; as, improvisation on the organ.
  2. That which is improvised; an impromptu.

Webster 1913