(1):

(n.) A bending of the knee, as in respect or courtesy.

(2):

(n.) A piece of timber or metal formed with an angle somewhat in the shape of the human knee when bent.

(3):

(n.) In man, the joint in the middle part of the leg.

(4):

(n.) The joint, or region of the joint, between the thigh and leg.

(5):

(n.) In the horse and allied animals, the carpal joint, corresponding to the wrist in man.

(6):

(v. t.) To supplicate by kneeling.