The phrase "war of words" refers to a heated verbal exchange or argument between two or more people, where each person is trying to outdo the other in using strong language and insults. It's an intense battle of wits and rhetoric, with both sides trying to score points by hurling accusations and insinuations at their opponents. The phrase can also be used more broadly to describe any situation where two parties engage in a bitter verbal confrontation, even if it doesn't involve physical violence or aggression.