(transitive) To ward off attacks against; to fight to protect; to guard.

(transitive) To support by words or writing; to vindicate, talk in favour of.

(transitive, law) To make legal defence of; to represent (the accused).

(sports) To focus one's energies and talents on preventing opponents from scoring, as opposed to focusing on scoring.

(sports) To attempt to retain a title, or attempt to reach the same stage in a competition as one did in the previous edition of that competition.

(poker slang) To call a raise from the big blind.

(transitive, obsolete) To ward off, repel (an attack or attacker).

(transitive, obsolete) To prevent, to keep (from doing something).

(transitive, intransitive, obsolete) To prohibit, forbid.