In humans, the joint or the region of the joint in the middle part of the leg between the thigh and the shank.

“Penny was wearing a miniskirt, so she skinned her exposed knees when she fell.”

In the horse and allied animals, the carpal joint, corresponding to the wrist in humans.

The part of a garment that covers the knee.

To kneel to.

“1605: I could as well be brought / To knee his throne and, squire-like, pension beg / To keep base life afoot. — William Shakespeare, King Lear II.ii”

To poke or strike with the knee.

To move on the knees; to use the knees to move.