breaker
A safety switch that stops electricity when there is trouble.
A breaker is something that breaks another thing, but the word takes on specific meanings depending on what's being broken.
The most common use refers to a circuit breaker, a safety device in your home's electrical panel that automatically cuts off power when too much electricity flows through a wire. Without breakers, overloaded wires could overheat and start fires. When you plug in too many devices at once and the power suddenly cuts out, a breaker has “tripped” to protect you. You can flip it back on once you've unplugged some devices.
On the ocean, breakers are waves that collapse as they approach shore. The wave builds higher and higher in shallow water until it can't support itself anymore and comes crashing down in a tumble of white foam. Surfers ride breakers, and the sound of breakers rolling onto a beach creates that rhythmic crashing we associate with the ocean.
In shipping and recycling, a ship breaker dismantles old vessels to salvage their metal and parts. And if you've been the icebreaker at a party, you've helped people relax and start talking when things felt awkward, breaking through social tension the way an icebreaker ship cuts through frozen waters.