Adulterated

adj. corrupted, inferior; watered down, made less concentrated

v. corrupt, make inferior; water down milk or other liquids

Adulterants are chemical substances which should not be contained within other substances (eg. food, beverages, fuels or pesticides) for legal or other reasons. Adulterants may be intentionally added to substances to reduce manufacturing costs, or for some deceptive or malicious purpose. Adulterants may also be accidentally or unknowingly introduced into substances. The addition of adulterants is called adulteration.
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Adjective
1. mixed with impurities
(synonym) adulterate, debased
(similar) impure

Verb
1. corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones; "adulterate liquor"
(synonym) stretch, dilute, debase
(hypernym) corrupt, spoil
(hyponym) water down
(verb-group) extend, stretch
(derivation) adulterant, adulterator
Adjective
1. mixed with impurities
(synonym) adulterated, debased
(similar) impure

(imp. & p. p.)
of Adulterate
  

1. Any pesticide whose strength or purity falls below the quality stated on its label. 2. A food, feed, or product that contains illegal pesticide residues.