adulterate
[v. uh-duhl-tuh-reyt; adj. uh-duhl-ter-it, -tuh-reyt] [v. əˈdʌltəˌreɪt; adj. əˈdʌltərɪt, -təˌreɪt]
verb
to make impure by adding extraneous, improper, or inferior ingredients
adjective
spurious, debased or impure
"All right! I've decided once and for all—we shall not adulterate our fine picnic with the likes of the Count!"