gap 
(găp)
(găp)n.
1.
a. An opening in a solid structure or surface; a cleft or breach: wriggled through a gap in the fence; a large gap in the wall where the artillery shell had exploded.
b. A break in a line of defense.
2. An opening through mountains; a pass.
3. A space between objects or points; an aperture: a gap between his front teeth.
4. An interruption of continuity: a nine-minute gap in the recorded conversation; needed to fill in the gaps in her knowledge.
5.
a. A conspicuous difference or imbalance; a disparity: a gap between revenue and spending; the widening gap between rich and poor.
b. A problematic situation resulting from such a disparity: the budget gap; the technology gap.
6. A spark gap.
v. gapped, gap·ping, gaps
v.tr.
1. To make an opening or openings in: a wall that was gapped.
2. To make or adjust a space between (objects or points) or in (a device): gap boards on a deck; gap a spark plug.
v.intr.
To be or become open: Her coat gapped open.
[Middle English, from Old Norse, chasm.]