transitive verb, intransitive verb improvised -·vised′, improvising -·vis′·ing

1. to compose, or simultaneously compose and perform, on the spur of the moment and without any preparation; extemporize
2. 1. to bring about, make, or do on the spur of the moment to improvise a solution to a problem
   2. to make, provide, or do with the tools and materials at hand, usually to fill an unforeseen and immediate need to improvise a bed out of leaves

Etymology: Fr improviser < It improvvisare < improvviso, unprepared < L improvisus, unforeseen < in-, not + provisus, pp. of providere, to foresee, anticipate: see provide