expression, noun
war of words; quarrel; dispute
A heated verbal argument or dispute, often implying a clash of opinions rather than physical conflict.
会議は口舌の争いに終始した。
The meeting was nothing but a war of words from start to finish.
彼らは些細なことで口舌の争いを始めた。
They started a quarrel over a trivial matter.
言い争い is a general term for a verbal dispute; 口舌の争い carries a slightly more formal or dramatic nuance.
Compound of 口舌 (こうぜつ, 'mouth and tongue', meaning words or speech) and 争い (あらそい, 'dispute'). The exact historical derivation is uncertain, but the expression is conventionally associated with verbal conflict.