countenance vs O.K.

countenance and O.K. both are nouns.

Word	Noun	Adjective	Verb	Adverb
countenance	Yes	No	Yes	No
O.K.	Yes	No	Yes	Yes

As nouns, O.K. is a hyponym of countenance; that is, O.K. is a word with a more specific, narrower meaning than countenance:

Other hyponyms of countenance include OK, okay, okeh, okey, visa, nihil obstat.

countenance (noun)	O.K. (noun)
the appearance conveyed by a person's face	an endorsement
the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
formal and explicit approval

countenance (verb)	O.K. (verb)
consent to, give permission; permit	give sanction to

countenance (adverb)	O.K. (adverb)
	in a satisfactory or adequate manner