Source : Webster's Revised Unabridged Dictionary (1913)

Gap \Gap\, n. (A["e]ronautics)
   The vertical distance between two superposed surfaces, esp.
   in a biplane.

Gap \Gap\, n. [OE. gap; cf. Icel. gap an empty space, Sw. gap
   mouth, breach, abyss, Dan. gab mouth, opening, AS. geap
   expanse; as adj., wide, spacious. See {Gape}.]
   An opening in anything made by breaking or parting; as, a gap
   in a fence; an opening for a passage or entrance; an opening
   which implies a breach or defect; a vacant space or time; a
   hiatus; a mountain pass.

         Miseries ensued by the opening of that gap. --Knolles.

         It would make a great gap in your own honor. --Shak.

   {Gap lathe} (Mach.), a turning lathe with a deep notch in the
      bed to admit of turning a short object of large diameter.
      

   {To stand in the gap}, to expose one's self for the
      protection of something; to make defense against any
      assailing danger; to take the place of a fallen defender
      or supporter.

   {To stop a gap}, to secure a weak point; to repair a defect.

Gap \Gap\, v. t.
   1. To notch, as a sword or knife.

   2. To make an opening in; to breach.

            Their masses are gapp'd with our grape. --Tennyson.

Source : WordNet®

gap
     n 1: a conspicuous disparity or difference as between two
          figures; "gap between income and outgo"; "the spread
          between lending and borrowing costs" [syn: {spread}]
     2: an open or empty space in or between things; "there was a
        small opening between the trees"; "the explosion made a
        gap in the wall" [syn: {opening}]
     3: a narrow opening; "he opened the window a crack" [syn: {crack}]
     4: a pass between mountain peaks [syn: {col}]
     5: an act of delaying or interrupting the continuity; "it was
        presented without commercial breaks" [syn: {break}, {interruption},
         {disruption}]
     [also: {gapping}, {gapped}]

gap
     v : make an opening or gap in [syn: {breach}]
     [also: {gapping}, {gapped}]

Source : Free On-Line Dictionary of Computing

GAP
     
         Groups Algorithms and Programming.
     
        A system for {symbolic mathematics} for computational discrete
        algebra, especially group theory, by Johannes Meier, Alice
        Niemeyer, Werner Nickel, and Martin Schonert of Aachen.  GAP
        was designed in 1986 and implemented 1987.  Version 2.4 was
        released in 1988 and version 3.1 in 1992.
     
        {Sun version (ftp://ftp.math.rwth-aachen.de/pub/gap)}.
     
        ["GAP 3.3 Manual, M. Schonert et al, Lehrstuhl D Math, RWTH
        Aachen, 1993].
     
        (1995-04-12)