A substance or agent that makes something unclean, impure, or poisoned; an unwanted chemical, biological, or radioactive material.
From contaminate + -ant (suffix forming nouns of agents or things that perform an action). Latin contaminare ('to defile') combines con- and taminare, possibly from tangere ('to touch'), suggesting something that corrupts through contact.
During the Flint water crisis, lead became a deadly contaminant that was invisible but devastating—it shows how something you can't see or taste can be more dangerous than something obvious.
Complete word intelligence in one call. Free tier — 50 lookups/day.