contaminate
v.v. to make something impure or dirty by mixing it with something harmful or unwanted. You use this when you talk about food, water, or air being ruined by a bad substance.
v. to make something impure or less pure by the addition of a foreign or harmful substance. Transitive — requires a direct object.
The factory waste might contaminate the local river.
If you leave the food out in the sun, it will contaminate the rest of the batch.
Environmental scientists are concerned that the chemical spill could contaminate the groundwater, making the surrounding land unsuitable for future agricultural use.
First attested in the early 15ᵗʰ century, in Middle English; from Middle English contaminaten (“to defile; to infect with desease”), from contaminat(e) (“sullied, defiled; infected with desease”, also used as the past participle of contaminaten) + -en (verb-forming suffix), from Latin contāminātus, the perfect passive participle of contāminō (“to touch together, blend, mingle, corrupt, defile”) (see -ate (verb-forming suffix)), which see for further informations. More at taste, tax, and taxi.
First attested in the early 15ᵗʰ century, in Middle English; from Middle English contaminat(e) (“sullied, defiled; infected with desease”, also used as the past participle of contaminaten), see -ate (adjective-forming suffix) and Etymology 1 for more. Participial usage up until Early Modern English.