1. a statement or situation that contains opposing or conflicting elements that cannot both be true
2. the act of saying that something someone else has said is wrong or not true

Examples

• There's a contradiction in his story about where he was last night.
• The witness testimony contained several contradictions.
• She spoke without contradiction from anyone in the room.
• His actions were in direct contradiction to his stated beliefs.
• The data shows a clear contradiction between the two studies.
• I won't tolerate any contradiction of my orders.
• The contradiction in the policy left employees confused.