(adjective) two things that cannot be simultaneously true: "The message that green business and profit are not mutually exclusive has become a favorite of the former Vice President."
Synonym: contradictory: "The articles of association and the shareholders' agreement contain contradictory provisions."

Antonym: reconcilable: "The member state's Companies Act was reconcilable with the new EU directive and thus it was not necessary to amend the national legislation."

Related words and concepts - Mutual means having the same relationship each to the other, or directed and received by each toward the other, or possessed in common, and is often used in these phrases:

mutually acceptable: acceptable to both parties. "Following extensive negotiations, the parties were able to reach a mutually acceptable solution."

mutually beneficial: good for both parties. "Parties enter into co-operation agreements when they find that pooling their resources will be mutually beneficial."

mutual mistake: the situation whereby two parties enter into a contract based on the same mistake of fact. "In most jurisdictions, payments made as the result of mutual mistake are fully refundable."

mutual assent: joint agreement. "By mutual assent of the parties, the proceedings were stayed pending appointment of a new arbitrator."
Source: Translegal