From Longman Dictionary of Contemporary Englishcircuit breakerˈcircuit ˌbreaker noun [countable] TEEa piece of equipment that stops an electric current reaching a machine if the machine becomes dangerous
Examples from the Corpus
circuit breaker• Even when the installation has been undertaken by an expert, the inclusion of a circuit breaker is a wise precaution.• Always use a circuit breaker for added safety.• You can, as a matter of course, help to protect yourself from electric shocks by using a circuit breaker.• Zahner attributed that, in part, to the circuit breaker system installed to prevent a repeat of the crash of 1987. 