n. Any piece of wood, metal, or other substance used to stop or fill a hole; a stopple. A flat oblong cake of pressed tobacco. A high, tapering silk hat. A worthless horse.
- (Building) A block of wood let into a wall, to afford a hold for nails. Fire plug, a street hydrant to which hose may be attached.
- Hawse plug (Naut.), a plug to stop a hawse hole.
- Plug and feather. (Stone Working) See Feather, n.
- Plug centerbit, a centerbit ending in a small cylinder instead of a point, so as to follow and enlarge a hole previously made, or to form a counterbore around it.
- Plug rod (Steam Eng.) A rod attached to the beam for working the valves, as in the Cornish engine.
- Plug valve (Mech.), a tapering valve, which turns in a case like the plug of a faucet.
- vb. To stop with a plug; to make tight by stopping a hole.