Adulterate

to debase or make impure by adding inferior materials or elements; use cheaper, inferior, or less desirable goods in the production of (any professedly genuine article):
to adulterate food.
impure or debased; cheapened in quality or purity.
(def 1).
historical examples

it is more soluble in both rectified spirit and water than any of the oils used to adulterate it.
cooley’s practical receipts, volume ii arnold cooley

montaigne was a gascon, and gasconisms adulterate the purity of his french.
cl-ssic french course in english william cleaver wilkinson

a copy in which costumes and colouring have been completely changed is but an adulterate representation.
the works of alexander pope, volume 1 alexander pope

so little was drunk in england that it was not worth while to adulterate it.
seeing and hearing george w. e. russell

peanuts are largely used to adulterate chocolate, and so far as wholesomeness is concerned, are not objectionable.
the peanut plant b. w. jones

but methinks he speaks with a spruce attic accent of adulterate spanish.
the works of john marston john marston

cotton is also used to adulterate woolen materials, and sometimes silk materials; “pure silk” so called, is often artificial silk.
clothing and health helen kinne

the london millers and bakers use immense quant-ties of bean flour to adulterate their flour and bread.
cooley’s cyclopdia of practical receipts and collateral information in the arts, manufactures, professions, and trades…, sixth edition, volume i arnold cooley

one is for charges of evading taxation, another for those who adulterate bread, and so forth.
a wanderer in venice e.v. lucas

the florets of this yield a beautiful pink dye (see above), and are sometimes used to adulterate hay saffron.
cooley’s cyclopdia of practical receipts and collateral information in the arts, manufactures, professions, and trades…, sixth edition, volume i arnold cooley

verb (əˈdʌltəˌreɪt)
(transitive) to debase by adding inferior material: to adulterate milk with water
adjective (əˈdʌltərɪt; -ˌreɪt)
adulterated; debased or impure
a less common word for adulterous
v.

1530s, back-formation from adulteration, or else from latin adulteratus, past participle of adulterare “to falsify, corrupt,” also “to commit adultery.” earlier verb was adulter (late 14c.). related: adulterated; adulterating.