improvise vs extemporize

improvise and extemporize both are verbs.

Word	Noun	Adjective	Verb	Adverb
improvise	No	No	Yes	No
extemporize	No	No	Yes	No

As verbs, improvise and extemporize are synonyms defined as:

Other synonyms of improvise include ad-lib, extemporise, improvize.

As verbs, improvise and extemporize are synonyms defined as:

improvise and extemporize: manage in a makeshift way; do with whatever is at hand

improvise (verb)	extemporize (verb)
perform without preparation	perform without preparation
manage in a makeshift way; do with whatever is at hand	manage in a makeshift way; do with whatever is at hand