This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

v. Third-person singular simple present indicative form of extemporize.

"Since then, Mr. Levin has been improvising in a variety of settings, including one performance in which he improvised the endings of unfinished works by Schubert, and concerts in which he invites audience members to submit musical themes during the intermission on which he then extemporizes."

extemporized    extemporizes    extemporizing   

execute    do    perform    contend    deal   

extemporizing-machine    off the cuff    play it by ear    off the top of one's head   

extemporaneous    extemporization    extempore    extemporisation   

extemporized    extemporizing   

improvise    composer