knob

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A rounded protuberance.
2. n. A rounded handle, as on a drawer or door.
3. n. A rounded control switch or dial.
4. n. A prominent rounded hill or mountain.

Century Dictionary and Cyclopedia

1. n. A rounded projection; a protuberance; a bunch; a knop.
2. n. A fleshy protuberance; a pimple.
3. n. A rounded projection forming the termination of something, as of a staff: specifically, the more or less ballshaped part of the handle for a door, drawer, or the like.
4. n. A prominent isolated hill; a hill generally: same as mound in Wisconsin and Iowa, and butte in the Cordilleran region. [Southern and western U. S.]
5. n. In entomology, a dilated outer portion of a part. Specifically — An expanded apical portion of an insect's antenna, as in a butterfly. In Diptera, the capitulum or outer portion of the halter or balancer. The distended outer portion of a fly's proboscis.
6. n. In a cannon, the spherical part at the rear end of the piece, forming the opposite extremity to the muzzle: it is a part of the cascabel. In ships' guns a breeching-loop takes the place of the knob.
7. n. In architecture, specifically, a bunch of leaves, flowers, or similar ornaments, as the boss at the intersection of ribs, the end of a label or other molding, or a bunch of foliage in a capital. In this sense also called knop and knot. See cut under boss.
8. n. Same as knobstick.
9. n. The rudiment of a deer's antler. Compare knobber.
10. To grow into knobs; bunch.
11. To produce a knob or knobs upon.
12. To free from knobs, as stone in the quarry, in rough-dressing it.
13. n. A small flock, less than 30, of ducks: an English sporting-term.

Wiktionary

1. n. A rounded protuberance, handle, or control switch.
2. n. A prominent rounded hill.
3. n. A rounded ornament on the hilt of an edged weapon; a pommel.
4. n. A prominent, rounded bump along a mountain ridge.
5. n. The penis.
6. n. A contemptible person.
7. n. A dollop, an amount just larger than a spoonful (usually referring to butter)
8. v. To have sex with.

GNU Webster's 1913

1. n. A hard protuberance; a hard swelling or rising; a bunch; a lump.
2. n. A knoblike ornament or handle.
3. n. A rounded hill or mountain.
4. n. See Knop.
5. v. To grow into knobs or bunches; to become knobbed.

WordNet 3.0

1. n. a round handle
2. n. an ornament in the shape of a ball on the hilt of a sword or dagger
3. n. a circular rounded projection or protuberance
4. n. any thickened enlargement