adulteration (n.) Look up adulteration at Dictionary.com
"act of adulterating," c. 1500, from Latin adulterationem (nominative adulteratio), noun of action from past participle stem of adulterare "corrupt, falsify; debauch; commit adultery," from ad- "to" (see ad-) + alterare "to alter" (see alter), though Watkins explains it as ad alterum "(approaching) another (unlawfully)." Meaning "a result of adulterating" is from 1650s.