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.