Im`pro*vise" (?), v. t. [imp. & p. p. Improvised (?); p. pr. & vb. n. Improvising.] [F. improviser, it. improvvisare, fr. improvviso unprovided, sudden, extempore, L. improvisus; pref. im- not + provisus foreseen, provided. See Proviso.] 1. To compose, recite, or sing extemporaneously, especially in verse; to extemporize; also, to play upon an instrument, or to act, extemporaneously.

2. To bring about, arrange, or make, on a sudden, or without previous preparation.

Charles attempted to improvise a peace.

3. To invent, or provide, offhand, or on the spur of the moment; as, he improvised a hammer out of a stone.

Im`pro*vise", v. i. To produce or render extemporaneous compositions, especially in verse or in music, without previous preparation; hence, to do anything offhand.

• to make something up or invent it as one goes; to proceed by guess rather than by a careful plan
       He had no speech prepared, so he improvised.
  
• to invent or create something quickly or without a plan
       They improvised a simple shelter with branches and the rope they were carrying.
  
• (music) to play without written music or prior plans; especially common in jazz and related genres
       She improvised a lovely solo.