What is Antinomy?

Legal Definition
Antinomy (Greek ἀντί, antí, "against, in opposition to," and νόμος, nómos, "law") refers to a real or apparent mutual incompatibility of two laws. It is a term used in logic and epistemology, particularly in the philosophy of Kant and Roberto Unger.

There are many examples of antinomy. A self-contradictory phrase such as "There is no absolute truth" can be considered an antinomy because this statement is suggesting in itself to be an absolute truth, and therefore denies itself any truth in its statement. A paradox such as "this sentence is false" can also be considered to be an antinomy; for the sentence to be true, it must be false, and vice versa.
-- Wikipedia
Legal Definition
A term used in the civil law to signify the real or apparent contradiction between two laws or two decisions. Merl. Repert. h. t. Vide Conflict of Laws.
-- Bouviers Law Dictionary
Legal Definition
A term used in logic and law to denote a real or apparent inconsistency or conflict between two authorities or propositions; same as antinomia, (q. v.)
-- Black's Law Dictionary