Definition of knee-cap:
(n) :
(anatomy) In humans, the joint or the region of the joint in the middle part of the leg between the thigh and the shank.
(n) :
In the horse and allied animals, the carpal joint, corresponding to the wrist in humans.
(n) :
The part of a garment that covers the knee.
(v) :
(transitive) To poke or strike with the knee.
(v) :
(reflexive) To move on the knees; to use the knees to move.
(n) :
A blow made with the knee; a kneeing.