meaning of contradictory
1. Affirming the contrary; implying a denial of what has been asserted; also, mutually contradicting; inconsistent.
2. Opposing or opposed; repugnant.
3. A proposition or thing which denies or opposes another; contrariety.
4. propositions with the same terms, but opposed to each other both in quality and quantity.
5. two propositions are contradictories if both cannot be true or both cannot be false at the same time