obviate vs rule out

obviate and rule out both are verbs.

Word	Noun	Adjective	Verb	Adverb
obviate	No	No	Yes	No
rule out	No	No	Yes	No

As verbs, rule out is a hyponym of obviate; that is, rule out is a word with a more specific, narrower meaning than obviate:

Other hyponyms of obviate include close out, preclude.

obviate (verb)	rule out (verb)
prevent the occurrence of; prevent from happening; to protect from or to keep away anything undesirable; to ward off	dismiss from consideration or a contest
get rid of something	include or exclude by determining judicially or in agreement with rules
	make impossible, especially beforehand