simper vs grin

simper and grin both are nouns.

Word	Noun	Adjective	Verb	Adverb
simper	Yes	No	Yes	No
grin	Yes	No	Yes	No

As nouns, grin is a hypernym of simper; that is, grin is a word with a broader meaning than simper:

simper: a silly self-conscious smile
grin: a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

Other hypernyms of simper include grinning, smile, smiling.

simper (noun)	grin (noun)
a silly self-conscious smile	a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

simper (verb)	grin (verb)
smile affectedly or derisively	to draw back the lips and reveal the teeth, in a smile, grimace, or snarl