Contaminate
late Middle English: from Latin contaminat- ‘made impure’, from the verb contaminare, from contamen ‘contact, pollution’, from con- ‘together with’ + the base of tangere ‘to touch’.
wiktionary
From Old French contaminer, from Latin contaminare(“to touch together, blend, mingle, corrupt, defile”), from contamen(“contact, defilement, contagion”), related to tangere.
etymonline
contaminate (v.)
early 15c., "infect with a disease, defile," from Latin contaminatus, past participle of contaminare "to defile, to corrupt, to deteriorate by mingling," originally "to bring into contact," from contamen "contact; pollution," from assimilated form of com "with, together" (see con-) + *tag-, base of tangere "to touch" (from PIE root *tag- "to touch, handle"). Related: Contaminant (1934).
