Noah Webster's New International Dictionary of the English Language

1. (v. t.) To justify; to clear from accusation; prove to be real or true.

2. (v. t.) To maintain or defend with success; to prove to be valid; to assert convincingly; to sustain against assault; as, to vindicate a right, claim, or title.

3. (v. t.) To support or maintain as true or correct, against denial, censure, or objections; to defend; to justify.

4. (v. t.) To maintain, as a law or a cause, by overthrowing enemies.

5. (v. t.) To liberate; to set free; to deliver.

6. (v. t.) To avenge; to punish; as, a war to vindicate or punish infidelity.