To add water to a mixture to dilute it; SYN. stretch, water down, dilute, debase.
Corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones

(Alternate spelling: adulterise).
To commit adultery.

1. To adulterate the purity of.
2. To make impure in a figurative sense.
3. To make radioactive by adding radioactive material.

ETYM French teint, p. p. of teindre to dye, tinge, from Latin tingere, tinctum. Related to Tinge, Tint.
To contaminate; to make impure.