1. to speak, perform, or compose something without preparation or planning; to improvise
Usage: third-person singular present tense of extemporize

Examples

• The jazz musician extemporizes a solo over the chord progression.
• When the teleprompter failed, the news anchor extemporizes the entire broadcast.
• She extemporizes a funny speech at her friend's wedding without any notes.
• The comedian extemporizes jokes based on audience reactions.
• He extemporizes a melody on the piano during the concert.
• The teacher extemporizes a lesson when the planned activity doesn't work out.