Adulterate

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

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

v. adulterate, debase, make inferior

adj. adulterate

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

(v. t.)
To defile by adultery.
  

(v. t.)
To corrupt, debase, or make impure by an admixture of a foreign or a baser substance; as, to adulterate food, drink, drugs, coin, etc.
  

(v. i.)
To commit adultery.
  

(a.)
Tainted with adultery.
  

(a.)
Debased by the admixture of a foreign substance; adulterated; spurious.