Pronunciation: (in"kun-sis'tunt),[key] —adj. 1. lacking in harmony between the different parts or elements; self-contradictory: an inconsistent story. 2. lacking agreement, as one thing with another or two or more things in relation to each other; at variance: a summary that is inconsistent with the previously stated facts. 3. not consistent in principles, conduct, etc.: He's so inconsistent we never know if he'll be kind or cruel. 4. acting at variance with professed principles.
5. Logic.incompatible (def. 4b).