DCHP-1 Online
gap ((n.)) Esp. Ont. 
n. an entrance between two islands (or an island and the mainland) to a harbor or inner bay.
- 1853 (1959) Just after you pass the island and enter the Lower Gap, there are three very small islands in a direct line with each other, that are known as the three brothers.
- 1937 "We'll go out the eastern gap, mate," hailed Jim. "Aye, aye, sir," I replied, bailing another three canfuls.
- 1945 There is only a brief exposure to the lake winds at "the upper gap" between Prince Edward County and Amherst Island. . . .
- 1853 (1959) Just after you pass the island and enter the Lower Gap, there are three very small islands in a direct line with each other, that are known as the three brothers.