reactor

re·ac·tor

noun \rē-ˈak-tər\

Definition of REACTOR

1

: one that reacts: as a : a chemical reagent b : an individual reacting to a stimulus c : an individual reacting positively to a foreign substance (as in a test for disease) <reactors to tuberculin>

2

a : a piece of equipment in which a chemical reaction and especially an industrial chemical reaction is carried out b : a device for the controlled release of nuclear energy (as for producing heat)