As verbs the difference between grinning and grimacing
is that grinning is present participle of lang=en while grimacing is present participle of lang=en.
As nouns the difference between grinning and grimacing
is that grinning is the act or expression of one who grins while grimacing is the act of making a grimace.
grinning
English
Verb
(
head)
- I’m grinning because someone told me a joke.
Noun
(
en noun)
The act or expression of one who grins.
* (Thomas Babington Macaulay)
- The agitations resembled the grinnings and writhings of a galvanized corpse, not the struggles of an athletic man.
grimacing
English
Verb
(head)
Noun
(
en noun)
The act of making a grimace.
* 1918 , H. G. Wells, Joan and Peter
- The next morning Oswald stopped short in the middle of his shaving, which in his case involved the most tortuous deflections and grimacings .