n. 25B6; noun
a black bill with a knob at the base : LUMP, bump, protuberance, protrusion, bulge, swelling, knot, node, nodule, ball; informal boss.
the knobs on the radio : DIAL, button.
she turned the knob on the door : DOORKNOB, (door) handle.
a few knobs of butter : NUGGET, lump, pat, ball, dollop, piece; N. Amer. informal gob.