- knob ► NOUN 1) a rounded lump or ball at the end or on the surface of something. 2) a ball-shaped handle on a door or drawer. 3) a round button on a machine. 4) a small lump of something. 5) chiefly N. Amer. a prominent round hill. 6) vulgar slang a man's penis.DERIVATIVES knobbed adjective knobby adjective.ORIGIN Low German knobbe 'knot, knob, bud' .
English terms dictionary. 2015.