Entry 2 senses · 2 variants Webster, 1913 Improvisate · Im·prov·i·sate · IPA a. v. t. & i. 01 a. Unpremeditated; impromptu; extempore. 1. Unpremeditated; impromptu; extempore.[R.] 02 v. t. & i. To improvise; to extemporize. imp. & p. p. Improvisated; p. pr. & vb. n. Improvisating 1. To improvise; to extemporize.