contaminate

Etymology

From Old French contaminer, from Latin contaminare (“to touch together, blend, mingle, corrupt, defile”), from contamen (“contact, defilement, contagion”), related to tangere. More at taste, tax, and taxi.

verb

1. (transitive) To make something dangerous or toxic by introducing impurities or foreign matter.
   This water is contaminated. It isn't safe to drink.
2. (transitive) To soil, stain, corrupt, or infect by contact or association.
   [Martin] Heidegger's repellent political beliefs do not contaminate his philosophical work. 12 April 2014, Michael Inwood, “Martin Heidegger: the philosopher who fell for Hitler [print version: Hitler's philosopher]”, in The Daily Telegraph (Review), London, page R11
3. (transitive) To make unfit for use by the introduction of unwholesome or undesirable elements.
   Do not contaminate the peanut butter with the jelly.
4. To infect, often with bad objects