smile vs smirk

smile and smirk both are nouns.

Word	Noun	Adjective	Verb	Adverb
smile	Yes	No	Yes	No
smirk	Yes	No	Yes	No

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

smile: a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement
smirk: a smile expressing smugness or scorn instead of pleasure

Other hyponyms of smile include simper.

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

smile: change one's facial expression by spreading the lips, often to signal pleasure
smirk: smile affectedly or derisively

Other hyponyms of smile include dimple, grin, beam, simper, sneer.

smile (noun)	smirk (noun)
a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement	a smile expressing smugness or scorn instead of pleasure

smile (verb)	smirk (verb)
change one's facial expression by spreading the lips, often to signal pleasure	smile affectedly or derisively
express with a smile