grinning vs smiling

grinning and smiling both are nouns.

Word	Noun	Adjective	Verb	Adverb
grinning	Yes	No	No	No
smiling	Yes	Yes	No	No

As nouns, grinning and smiling are synonyms defined as:

grinning and smiling: a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

Other synonyms of grinning include grin, smile.

grinning (noun)	smiling (noun)
a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement	a facial expression characterized by turning up the corners of the mouth; usually shows pleasure or amusement

grinning (adjective)	smiling (adjective)
	smiling with happiness or optimism