reactor
/reaɡˈtoɾ/ · B2 · noun · m
atomic reactor
🚀 re-actor = something that acts back: action, equal and opposite reaction
Reactor comes from react: a device built on reaction. Newton's third law says every action has a reaction, and that is how a rocket or jet engine pushes forward. In a nuclear reactor, atoms react with each other to release energy. Stress is on the last syllable: reac-TOR.