Plug n. 1.Any piece of wood, metal, or other substance used to stop or fill a hole; a stopple.
2.A flat oblong cake of pressed tobacco. (U. S.)
3.A high, tapering silk hat. (Slang, U.S.)
4.A worthless horse. (Slang, U.S.)
5.(Building) A block of wood let into a wall, to afford a hold for nails.
6.An act of plugging (6); a brief mention for the sake of publicity or advertisement, especially during a public event not specifically intended for advertising purposes; as, he put in a plug for his favorite charity.
Breech plug (Gun.), in breech-loading guns, the metal plug or cylinder which closes the aperture in the breech, through which the gun is loaded.
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 v. t. (past & past part. plugged; pres. part. plugging) 1.To stop with a plug; to make tight by stopping a hole.
2.To briefly publicize or advertise, especially during a public event not specifically intended for advertising purposes; as, during the interview he plugged his new book.
Synonyms: put in a plug for.
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