(1):

(a.) Affirming the contrary; implying a denial of what has been asserted; also, mutually contradicting; inconsistent.

(2):

(a.) Opposing or opposed; repugnant.

(3):

(n.) A proposition or thing which denies or opposes another; contrariety.

(4):

(n.) propositions with the same terms, but opposed to each other both in quality and quantity.