Word parts poison + -less Adjective Positive poisonless Comparative none Superlative none If something is poisonless, is does not have any poison in it. Synonyms: nontoxic, nonpoisonous and unpoisonous Antonyms: toxic, venomous and poisonous That garter snake is poisonless.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads