The state of being inconsistent, or not staying the same throughout. The inconsistency in his statements made it difficult to trust his account of the events.
A thing that is not in harmony or agreement with other things. There was an inconsistency between the two reports that needed to be addressed.
(logic, mathematics) A set of propositions that yields both a statement and its negation; a contradiction within a formal system. If a theory allows both a proposition and its denial to be proven, it contains an inconsistency.