Pronunciation: (ik-stem'pu-rīz"), [key]
—v., -rized, -riz•ing.
1. to speak extemporaneously: He can extemporize on any of a number of subjects.
2. to sing, or play on an instrument, composing the music as one proceeds; improvise.
3. to do or manage something in a makeshift way.
1. to make or devise extempore.
2. Music.to compose offhand; improvise. Also, esp. Brit.,ex•tem'po•rise".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.