What is "improvising"

Improvise \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, do, or make, immediately or on short notice, without previous preparation and with no known precedent as a guide.

   Charles attempted to improvise a peace.
   --Motley.

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

n. improvisation vb. (present participle of improvise English)