taint ‧ ed /ˈteɪntəd, ˈteɪntɪd/ BrE AmE adjective especially American English
1 . a tainted substance, especially food or drink, is not safe because it is spoiled or contains a harmful substance or poison:
a tainted blood supply
2 . affected or influenced by something illegal, dishonest, or morally wrong:
a tainted witness