Boss

Part of speech: noun (n.)

1. Any protuberant part; a round, swelling part or body; a knoblike process; as, a boss of wood.

2. A protuberant ornament on any work, either of different material from that of the work or of the same, as upon a buckler or bridle; a stud; a knob; the central projection of a shield. See Umbilicus.

3. A projecting ornament placed at the intersection of the ribs of ceilings, whether vaulted or flat, and in other situations.

4. A wooden vessel for the mortar used in tiling or masonry, hung by a hook from the laths, or from the rounds of a ladder. Gwilt.

5. The enlarged part of a shaft, on which a wheel is keyed, or at the end, where it is coupled to another.

6. A swage or die used for shaping metals.

7. A head or reservoir of water. [Obs.]

Part of speech: noun (n.)

A master workman or superintendent; a director or manager; a political dictator. [Slang, U. S.]

Part of speech: verb (v.)

To ornament with bosses; to stud.