Entry 1 sense Webster, 1913 Contamination /(kŏn*tăm`ĭ*nā"shŭn)/ · Con·tam·i·na·tion · IPA /kənˌtæm.əˈneɪ.ʃən/ 01 n. The act or process of contaminating; pollution; defilement; taint; also, that which contaminates. 1. The act or process of contaminating; pollution; defilement; taint; also, that which contaminates.