Ward  n. 1 separate part of a hospital or room for a particular group of patients. 2 administrative division of a constituency. 3 a minor under the care of a guardian or court. B (in full ward of court) minor or mentally deficient person placed under the protection of a court. 4 (in pl.) The corresponding notches and projections in a key and a lock. 5 archaic guardian's control.  ward off 1 parry (a blow). 2 avert (danger etc.). [old english]