Meaning of REACTOR in English

[] n (ca. 1904) 1: one that reacts

2: a device (as a coil, winding, or conductor of small resistance) used to introduce reactance into an alternating-current circuit 3 a: a vat for an industrial chemical reaction b: a device for the controlled release of nuclear energy (as for producing heat)

Merriam-Webster English vocab.      Английский словарь Merriam Webster.