Meaning

1. To ward off attacks against; to fight to protect; to guard.
2. To support by words or writing; to vindicate, talk in favour of.
3. To make legal defence of; to represent (the accused).
4. To focus one's energies and talents on preventing opponents from scoring, as opposed to focusing on scoring.
5. To attempt to retain a title, or attempt to reach the same stage in a competition as one did in the previous instance of that competition.
6. (slang) To call a raise from the big blind.
7. (obsolete) To ward off, repel (an attack or attacker).
8. (obsolete) To prevent, to keep (from doing something).
9. (obsolete) To prohibit, forbid.