1. [n]  the act of concealing yourself and lying in wait to attack by surprise
2. [n]  a hazard on a golf course
3. [n]  a device in which something (usually an animal) can be caught and penned
4. [n]  a light two-wheeled carriage
5. [n]  a device to hurl clay pigeons into the air for trapshooters
6. [n]  drain consisting of a U-shaped section of drainpipe that holds liquid and so prevents a return flow of sewer gas
7. [n]  informal terms for the mouth
8. [n]  something (often something deceptively attractive) that catches you unawares; "the exam was full of trap questions"; "it was all a snare and delusion"
9. [v]  to hold fast or prevent from moving; "The child was pinned under the fallen tree"
10. [v]  catch in or as if in a trap; "The men trap foxes"
11. [v]  hold or catch as if in a trap; "The gaps between the teeth trap food particles"
12. [v]  place in a confining or embarrassing position; "He was trapped in a difficult situation"

1. \Trap\, v. t. [imp. & p. p. {Trapped}; p. pr. & vb. n.
   {Trapping}.] [Akin to OE. trappe trappings, and perhaps from
   an Old French word of the same origin as E. drab a kind of
   cloth.]
   To dress with ornaments; to adorn; -- said especially of
   horses.
         Steeds . . . that trapped were in steel all glittering.
                                                  --Chaucer.
         To deck his hearse, and trap his tomb-black steed.
                                                  --Spenser.
         There she found her palfrey trapped In purple blazoned
         with armorial gold.                      --Tennyson.
   

2. \Trap\, n. [Sw. trapp; akin to trappa stairs, Dan. trappe,
   G. treppe, D. trap; -- so called because the rocks of this
   class often occur in large, tabular masses, rising above one
   another, like steps. See {Tramp}.] (Geol.)
   An old term rather loosely used to designate various
   dark-colored, heavy igneous rocks, including especially the
   feldspathic-augitic rocks, basalt, dolerite, amygdaloid,
   etc., but including also some kinds of diorite. Called also
   {trap rock}.
   {Trap tufa}, {Trap tuff}, a kind of fragmental rock made up
      of fragments and earthy materials from trap rocks.
   

3. \Trap\, a.
   Of or pertaining to trap rock; as, a trap dike.
   

4. \Trap\, n. [OE. trappe, AS. treppe; akin to OD. trappe,
   OHG. trapo; probably fr. the root of E. tramp, as that which
   is trod upon: cf. F. trappe, which is trod upon: cf. F.
   trappe, which perhaps influenced the English word.]
   1. A machine or contrivance that shuts suddenly, as with a
      spring, used for taking game or other animals; as, a trap
      for foxes.
            She would weep if that she saw a mouse Caught in a
            trap.                                 --Chaucer.
   2. Fig.: A snare; an ambush; a stratagem; any device by which
      one may be caught unawares.
            Let their table be made a snare and a trap. --Rom.
                                                  xi. 9.
            God and your majesty Protect mine innocence, or I
            fall into The trap is laid for me!    --Shak.
   3. A wooden instrument shaped somewhat like a shoe, used in
      the game of trapball. It consists of a pivoted arm on one
      end of which is placed the ball to be thrown into the air
      by striking the other end. Also, a machine for throwing
      into the air glass balls, clay pigeons, etc., to be shot
      at.
   4. The game of trapball.
   5. A bend, sag, or partitioned chamber, in a drain, soil
      pipe, sewer, etc., arranged so that the liquid contents
      form a seal which prevents passage of air or gas, but
      permits the flow of liquids.
   6. A place in a water pipe, pump, etc., where air accumulates
      for want of an outlet.
   7. A wagon, or other vehicle. [Colloq.] --Thackeray.
   8. A kind of movable stepladder. --Knight.
   {Trap stairs}, a staircase leading to a trapdoor.
   {Trap tree} (Bot.) the jack; -- so called because it
      furnishes a kind of birdlime. See 1st {Jack}.
   

5. \Trap\, v. t. [AS. treppan. See {Trap} a snare.]
   1. To catch in a trap or traps; as, to trap foxes.
   2. Fig.: To insnare; to take by stratagem; to entrap. ``I
      trapped the foe.'' --Dryden.
   3. To provide with a trap; as, to trap a drain; to trap a
      sewer pipe. See 4th {Trap}, 5.
   

6. \Trap\, v. i.
   To set traps for game; to make a business of trapping game;
   as, to trap for beaver.
   

1. A program interrupt, usually an interrupt caused by some exceptional situation in the user program. In most cases, the OS performs some action, then returns control to the program.

2. To cause a trap. "These instructions trap to the monitor." Also used transitively to indicate the cause of the trap. "The monitor traps all input/output instructions."

This term is associated with assembler programming ("interrupt" or "exception" is more common among HLL programmers) and appears to be fading into history among programmers as the role of assembler continues to shrink. However, it is still important to computer architects and systems hackers (see system, sense 1), who use it to distinguish deterministically repeatable exceptions from timing-dependent ones (such as I/O interrupts).

[Jargon File]