Gap n.
 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.
    Miseries ensued by the opening of that gap.   --Knolles.
    It would make a great gap in your own honor.   --Shak.
 2. Aëronautics The vertical distance between two superposed surfaces, esp. in a biplane.
 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.