Pronunciation: (di-fend'),[key] —v.t. 1. to ward off attack from; guard against assault or injury (usually fol. by from or against): The sentry defended the gate against sudden attack. 2. to maintain by argument, evidence, etc.; uphold: She defended her claim successfully. 3. to contest (a legal charge, claim, etc.).
4. Law.to serve as attorney for (a defendant): He has defended some of the most notorious criminals. 5. to support (an argument, theory, etc.) in the face of criticism; prove the validity of (a dissertation, thesis, or the like) by answering arguments and questions put by a committee of specialists.
6. to attempt to retain (a championship title, position, etc.), as in a competition against a challenger.