contaminate

verb

1. 1

   To make something dangerous or toxic by introducing impurities or foreign matter.

   “This water is contaminated. It isn't safe to drink.”

2. 2

   To soil, stain, corrupt, or infect by contact or association.

3. 3

   To make unfit for use by the introduction of unwholesome or undesirable elements.

   “Do not contaminate the peanut butter with the jelly.”

4. 4

   To infect, often with bad objects