What is the meaning of Reactor?

A person who responds to a suggestion, stimulation or other influence.

A structure used to contain chemical or other reactions.

A device which uses atomic energy to produce heat.

A chemical substance which responds to the presence of, or contact with, another substance.

atomic reactor

chemical reactor

Pre-reform spelling (used until 1943 in Brazil and 1990 in Portugal) of reator. Still used in countries where the agreement hasn't come into effect; may occur as a sporadic misspelling.

reactor

jet engine

rocket engine

atomic reactor

chemical reactor

Source: wiktionary.org