Definitions

1. noun

A device or system that uses nuclear fission or other processes to generate power or produce radioactive materials.

“The nuclear reactor was shut down for maintenance.”

2. noun

A device or system that uses a chemical reaction to produce a desired effect, such as propulsion in a spacecraft.

“The rocket’s reactor provided the thrust needed to escape Earth’s atmosphere.”

3. noun

A person or thing that causes a reaction or response, often in a social or emotional context.

“The comedian was the reactor that got the crowd laughing.”