'Extemporization' definitions:

Definition of 'extemporization'

From: WordNet
noun
A performance given extempore without planning or preparation [syn: extemporization, extemporisation, improvisation]

Definition of 'Extemporization'

From: GCIDE
  • Extemporization \Ex*tem`po*ri*za"tion\, n. The act of extemporizing; the act of doing anything extempore. [1913 Webster]