Home › Words › R › radiotoxinradiotoxinradiotoxin · noun — any radiotoxic substance.Definition from Wiktionary (CC BY-SA 3.0).Among words judged in Lexicurio's Arena, radiotoxin ranks #32,438 of 42,858 for Qualifying.EtymologyFrom radio- + toxin.nounAny radiotoxic substance.e.g.“Airborne plutonium is a radiotoxin.”Definitions & examples from Wiktionary (CC BY-SA 3.0).