difference between "to grouse" and "to complain"?
Solution 1:
To grouse is to complain mainly about trivial things:
to complain, often about unimportant things.
(Macmillan Dictionary)
as Vocabulary.com notes:
People's excitement about the rise of the Internet has been largely replaced by disappointment that it's turned out to be essentially a forum for people to grouse. No disappointment is too small to grouse about on the Internet. Did you stub your toe? Grouse about it in your blog! Did your sister tattletale? Get online and start grousing. "I grouse, therefore I am," might be the motto of the Internet.