The term 'FIGHT AGAINST' can be broken down into four crossword solutions: OPPOSE (6 letters), RESIST (6 letters), COMBAT (6 letters), and lock horns with (13 letters). OPPOSE and RESIST both mean to actively disagree with or challenge something, while COMBAT implies a more physical struggle. Lock horns with is an idiom meaning to engage in a heated argument or confrontation. All of these terms refer to a type of opposition or resistance to something, whether it be an idea, a person, or a situation.