Breaker is defined as a device usually found in the home, on a pole or in a substation. It is designed to open automatically when a fault occurs. It can be operated manually or automatically.

Other definition:

In meteorology, a breaker is a sea surface wave that has become too steep to be stable and that breaks on the shore or in the open ocean.
Breakers can be classified into four categories:

1) A spilling breaker breaks gradually over a considerable distance;

2) plunging breakers tend to curl over and break with a crash;

3) surging breakers peak up, but then instead of spilling or plunging, they surge up on the beach face;