The Collaborative International Dictionary of English v.0.48:

Gap \Gap\ (g[a^]p), 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.]
   1. 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.
      [1913 Webster]

            Miseries ensued by the opening of that gap.
                                                  --Knolles.
      [1913 Webster]

            It would make a great gap in your own honor. --Shak.
      [1913 Webster]

   2. (A["e]ronautics) The vertical distance between two
      superposed surfaces, esp. in a biplane.
      [Webster 1913 Suppl.]

   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.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Gap \Gap\, v. t.
   1. To notch, as a sword or knife.
      [1913 Webster]

   2. To make an opening in; to breach.
      [1913 Webster]

            Their masses are gapp'd with our grape. --Tennyson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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: gap, 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, gap]
    3: a narrow opening; "he opened the window a crack" [syn: gap,
       crack]
    4: a pass between mountain peaks [syn: col, gap]
    5: a difference (especially an unfortunate difference) between
       two opinions or two views or two situations
    6: an act of delaying or interrupting the continuity; "it was
       presented without commercial breaks"; "there was a gap in his
       account" [syn: break, interruption, disruption, gap]
    v 1: make an opening or gap in [syn: gap, breach]

The Free On-line Dictionary of Computing (19 January 2023):

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)