wince vs grimace

wince and grimace both are nouns.

Word	Noun	Adjective	Verb	Adverb
wince	Yes	No	Yes	No
grimace	Yes	No	Yes	No

As verbs, grimace is a hypernym of wince; that is, grimace is a word with a broader meaning than wince:

Other hypernyms of wince include make a face, pull a face.

wince (noun)	grimace (noun)
a reflex response to sudden pain	a contorted facial expression
the facial expression of sudden pain

wince (verb)	grimace (verb)
make a face indicating disgust or dislike	contort the face to indicate a certain mental or emotional state
draw back, as with fear or pain