A gap or opening made by breaking or battering, as in a wall, fortification or levee / embankment; the space between the parts of a solid body rent by violence
2
A breaking up of amicable relations, a falling-out.
3
A breaking of waters, as over a vessel or a coastal defence; the waters themselves
A clear breach is when the waves roll over the vessel without breaking. A clean breach is when everything on deck is swept away.