Fender-bender and Meltdown

Fender-bender noun - A collision between motor vehicles that produces minor damage.

Meltdown and fender-bender are semantically related. In some cases you can use "Meltdown" instead a noun phrase "Fender-bender".

Meltdown noun - Severe overheating of the core of a nuclear reactor resulting in the core melting and radiation escaping.

Fender-bender and meltdown are semantically related. Sometimes you can use "Fender-bender" instead a noun "Meltdown".