The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. A flat oblong cake of pressed tobacco. [U. S.]
      [1913 Webster]

   3. A high, tapering silk hat. [Slang, U.S.]
      [1913 Webster]

   4. A worthless horse. [Slang, U.S.]
      [1913 Webster]

   5. (Building) A block of wood let into a wall, to afford a
      hold for nails.
      [1913 Webster]

   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.
      [PJC]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hawse \Hawse\ (h[add]z or h[add]s; 277), n. [Orig. a hawse hole,
   or hole in the bow of the ship; cf. Icel. hals, h[=a]ls,
   neck, part of the bows of a ship, AS. heals neck. See
   Collar, and cf. Halse to embrace.]
   1. A hawse hole. --Harris.
      [1913 Webster]

   2. (Naut.)
      (a) The situation of the cables when a vessel is moored
          with two anchors, one on the starboard, the other on
          the port bow.
      (b) The distance ahead to which the cables usually extend;
          as, the ship has a clear or open hawse, or a foul
          hawse; to anchor in our hawse, or athwart hawse.
      (c) That part of a vessel's bow in which are the hawse
          holes for the cables.
          [1913 Webster]

   Athwart hawse. See under Athwart.

   Foul hawse, a hawse in which the cables cross each other,
      or are twisted together.

   Hawse block, a block used to stop up a hawse hole at sea;
      -- called also hawse plug.

   Hawse piece, one of the foremost timbers of a ship, through
      which the hawse hole is cut.

   Hawse plug. Same as Hawse block (above).

   To come in at the hawse holes, to enter the naval service
      at the lowest grade. [Cant]

   To freshen the hawse, to veer out a little more cable and
      bring the chafe and strain on another part.
      [1913 Webster] hawsehole