Added 10 October 2026 reactor /ɹiˈæktɚ/ noun Categories: ThingsUncommon Words noun ! Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about reactor at Wordnik → Where our words come from → 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. Related Words: nmcnuclearnukegeneratorarcheaterblastfurnacestovecuttercentral Back to today's word