Definition of knobs:
(n) :
A rounded protuberance, especially one arising from a flat surface; a fleshy lump or caruncle.
(n) :
A rounded control switch that can be turned on its axis, designed to be operated by the fingers.
(n) :
A ball-shaped part of a handle, lever, etc., designed to be grabbed by the hand.
(n) :
A rounded ornament on the hilt of an edged weapon; a pommel.
(n) :
A prominent, rounded bump along a mountain ridge.
(n) :
(geography, chiefly Appalachia, Lancashire) A prominent rounded hill.