Also found in: Thesaurus.
v. ex·tem·po·rized, ex·tem·po·riz·ing, ex·tem·po·riz·es
To do or perform (something) without prior preparation or practice: extemporized an acceptance speech.
To perform an act or utter something in an impromptu manner; improvise: "[When] the house lights dimmed, she could no longer read what she had written and was forced to extemporize" (Dale Peterson).
ex·tem′po·ri·za′tion (-pər-ĭ-zā′shən) n.