Tending to contradict or oppose, contrarious.
That contradicts something, such as an argument.
That is diametrically opposed to something.
That is itself a contradiction.
Mutually exclusive.
Either of a pair of propositions, that cannot both be true or both be false.
Provoking strife, controversy or discord.
One who makes specious arguments; one who is disputatious.
A type of dialogue or argument where the participants do not have any reasonable goal. The aim is to argue for the sake of conflict, and often to see who can yell the loudest.