4. A worthless horse. [Slang, U.S.]
5. (Building)
Defn: 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. [U. S.] — Hawse plug (Naut.), a plug to stop a hawse hole. — Plug and feather. (Stone Working) See Feather, n., 7. — 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.
PLUG
Plug, v. t. [imp. & p. p. Plugged; p. pr. & vb. n. Plugging.]
Defn: To stop with a plug; to make tight by stopping a hole.
PLUG BOARD
Plug board. (Elec.)
Defn: A switchboard in which connections are made by means of plugs.
PLUGGER
Plug"ger, n.
Defn: One who, or that which, plugs.
PLUGGING
Plug"ging, n.