Repeal means to revoke or rescind, especially by an official or formal act. To repeal a law is to void an existing law, by passage of a repealing statute, or by public vote on a referendum. A law may be repealed by implication, by passage of a statute which is inconsistent with the old statute.
Repeal of constitutional provisions requires an amendment, such as the 21st Amendment's repeal of prohibition, which repealed the 18th Amendment. Without a statutory provision otherwise, when a statute repeals another, and afterwards the repealing statute is itself repealed, the first statute is revived.
