ad-lib vs execute

ad-lib is a noun but execute is not a noun.

Word	Noun	Adjective	Verb	Adverb
ad-lib	Yes	Yes	Yes	No
execute	No	No	Yes	No

As verbs, execute is a hypernym of ad-lib; that is, execute is a word with a broader meaning than ad-lib:

Other hypernyms of ad-lib include do, perform.

ad-lib (noun)	execute (noun)
remark made spontaneously without prior preparation

ad-lib (adjective)	execute (adjective)
with little or no preparation or forethought
said or done without having been planned or written in advance

ad-lib (verb)	execute (verb)
perform without preparation	sign in the presence of witnesses
	put in effect
	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