ADULTERATOR

adulterator

(noun) a changer who lessens the purity or effectiveness of a substance

adulterant, adulterator

(noun) any substance that lessens the purity or effectiveness of a substance; “it is necessary to remove the adulterants before use”

Source: WordNet® 3.1

Noun

adulterator (plural adulterators)

One who or that which adulterates, or harms the purity of, something.

Source: Wiktionary

A*dul"ter*a`tor, n. Etym: [L.]

Definition: One who adulterates or corrupts. [R.] Cudworth.

Source: Webster’s Unabridged Dictionary 1913 Edition