con·tam·i·nate / kənˈtaməˌnāt/ • v. [tr.] (often be contaminated) make (something) impure by exposure to or addition of a poisonous or polluting substance: the site was found to be contaminated by radioactivity | fig. the entertainment industry is able to contaminate the mind of the public. DERIVATIVES: con·tam·i·nant / -ˈtamənənt/ n.con·tam·i·na·tion / -ˌtaməˈnāshən/ n.con·tam·i·na·tor / -ˌnātər/ n.

contaminate XV. f. pp. stem of L. contamināre, f. contāmen-, -min- contact, pollution, for *contagmen, f. CON- + *tag-, base of tangere touch; see -ATE 3.
So contamination XV. — late L.