trigger

trigger
    n 1: lever that activates the firing mechanism of a gun [syn:
         {gun trigger}, {trigger}]
    2: a device that activates or releases or causes something to
       happen
    3: an act that sets in motion some course of events [syn:
       {trigger}, {induction}, {initiation}]
    v 1: put in motion or move to act; "trigger a reaction";
         "actuate the circuits" [syn: {trip}, {actuate}, {trigger},
         {activate}, {set off}, {spark off}, {spark}, {trigger off},
         {touch off}]
    2: release or pull the trigger on; "Trigger a gun"
    

Trigger \Trig"ger\, n. [For older tricker, from D. trekker, fr.
   trekken to draw, pull. See {Trick}, n.]
   1. A catch to hold the wheel of a carriage on a declivity.
      [1913 Webster]

   2. (Mech.) A piece, as a lever, which is connected with a
      catch or detent as a means of releasing it; especially
      (Firearms), the part of a lock which is moved by the
      finger to release the cock and discharge the piece.
      [1913 Webster]

   {Trigger fish} (Zool.), a large plectognath fish ({Balistes
      Carolinensis} or {Balistes capriscus}) common on the
      southern coast of the United States, and valued as a food
      fish in some localities. Its rough skin is used for
      scouring and polishing in the place of sandpaper. Called
      also {leather jacket}, and {turbot}.
      [1913 Webster]
    

trigger

   <database> An action causing the automatic invocation of a
   procedure, for instance to preserve {referential integrity}.
   A triggers goes into effect when a user attempts to modify
   data with an insert, delete, or update command.  A trigger can
   instruct the system to take any number of actions when a
   specified change is attempted.  By preventing incorrect,
   unauthorized, or inconsistent changes to data, triggers help
   maintain the integrity of the database.

   [Sybase SQL Server Release 10.0 Transact-SQL User's Guide].

   (1995-02-22)