approve vs sanction

approve is not a noun while sanction is a noun.

Word	Noun	Adjective	Verb	Adverb
approve	No	No	Yes	No
sanction	Yes	No	Yes	No

As verbs, approve and sanction are synonyms defined as:

Other synonyms of approve include O.K., okay.

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

Other hyponyms of approve include sanctify, visa, back, endorse, indorse, plump for, plunk for, support, confirm, greenlight.

approve (noun)	sanction (noun)
	the act of final authorization
	a mechanism of social control for enforcing a society's standards
	official permission or approval
	formal and explicit approval

approve (verb)	sanction (verb)
judge to be right or commendable; think well of	give sanction to
give sanction to	give religious sanction to, such as through an oath
	give authority or permission to