(1) To abolish or annul. (2) To ignore or treat as if nonexistent.
The proposed constitutional amendment would abrogate fundamental rights of citizens that had long been protected by the courts.
The Latin prefix ab- sometimes functions like the English prefix un-, so if the ancient Romans wanted to "un-propose" something -- that is, propose that something no longer be done -- the verb they used was abrogare, from which we get abrogate. Today, members of our Senate might consider abrogating a treaty if serious questions were raised about the way in which it was negotiated. Similarly, a manufacturer faced with large increases in the cost of materials may feel justified in abrogating contracts with its customers. And policies requiring doctors to give out information about their patients are said to abrogate the confidential patient-doctor relationship.