circuit breaker

WordReference Random House Learner's Dictionary of American English © 2025

ˈcir•cuit ˌbreak•er, n. [countable]

1. Electricity a device for stopping the flow of electricity through an electric circuit:
   old fuses replaced with circuit breakers.

WordReference Random House Unabridged Dictionary of American English © 2025

cir′cuit break′er, 

1. Electricity Also called breaker. a device for interrupting an electric circuit to prevent excessive current, as that caused by a short circuit, from damaging the apparatus in the circuit or from causing a fire.
2. Business any property-tax relief measure that reduces or limits property taxes for certain eligible taxpayers, as those with low income or the elderly.
• 1870–75, American.

Collins Concise English Dictionary © HarperCollins Publishers::

circuit breaker noun

1. a device that under abnormal conditions, such as a short circuit, interrupts the flow of current in an electrical circuit
   Compare fuse26
2. Also: circuit break an action that is taken in order to prevent an undesirable situation from continuing or escalating: a circuit breaker to head off a panic in the stock market