To complain or find fault in a petty or disagreeable way:
To act as a critic.
To quibble is defined as to use petty, trivial expressions or arguments when discussing an issue.
To argue or find fault over trivial matters; raise petty objections.
Find another word for nitpick. In this page you can discover 4 synonyms, antonyms, idiomatic expressions, and related words for nitpick, like: carp, criticize, quibble and cavil.