execute vs improvise

execute and improvise both are verbs.

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

As verbs, improvise is a hyponym of execute; that is, improvise is a word with a more specific, narrower meaning than execute:

execute (verb)	improvise (verb)
sign in the presence of witnesses	perform without preparation
put in effect	manage in a makeshift way; do with whatever is at hand
carry out or perform an action
kill as a means of socially sanctioned punishment
murder in a planned fashion
carry out the legalities of
carry out a process or program, as on a computer or a machine