attempt vs stab

attempt and stab both are nouns.

Word	Noun	Adjective	Verb	Adverb
attempt	Yes	No	Yes	No
stab	Yes	No	Yes	No

As nouns, stab is a hyponym of attempt; that is, stab is a word with a more specific, narrower meaning than attempt:

attempt: earnest and conscientious activity intended to do or accomplish something
stab: informal words for any attempt or effort

attempt (noun)	stab (noun)
earnest and conscientious activity intended to do or accomplish something	a strong blow with a knife or other sharp pointed instrument
the act of attacking	informal words for any attempt or effort
	a sudden sharp feeling

attempt (verb)	stab (verb)
enter upon an activity or enterprise	stab or pierce
make an effort or attempt	poke or thrust abruptly
	use a knife on