knob

noun

1. a rounded lump or protuberance
2. 1. a handle, usually round, of a door, drawer, etc.
   2. a similar device which is turned to control operations of electronic or electrical equipment, as a radio or TV receiver
3. a rounded hill or mountain; knoll

Origin: ME knobbe < or akin to Du, a knot, knob, bud < IE *gn-eu-bh < base *gen-: see knead