炮尾连接螺

Plug \Plug\, n. [Akin to D. plug, G. pflock, Dan. pl["o]k, plug,
Sw. plugg; cf. W. ploc.]
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.

{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.