adulterate
Adulterate (adj) means Made less pure because another substance has been mixed into it.
Etymology
From Latin adulterātus (“adulterate, adulterated, defiled, polluted, counterfeited”), perfect passive participle of adulterō (“to adulterate, defile, commit adultery (with), counterfeit”) (see -ate (adjective-forming suffix)), from ad- (“to, in the direction of”) + alter (“other”) + -ō (verb-forming suffix), literally “to go after someone else”. Equivalent to adultery + -ate.