sanction vs countenance

sanction and countenance both are nouns.

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

As nouns, sanction and countenance are synonyms defined as:

Other synonyms of sanction include endorsement, imprimatur, indorsement, warrant.

sanction (noun)	countenance (noun)
the act of final authorization	the appearance conveyed by a person's face
a mechanism of social control for enforcing a society's standards	the human face (`kisser' and `smiler' and `mug' are informal terms for `face' and `phiz' is British)
official permission or approval	formal and explicit approval
formal and explicit approval

sanction (verb)	countenance (verb)
give sanction to	consent to, give permission; permit
give religious sanction to, such as through an oath
give authority or permission to