Entry 2 senses · 2 variants Webster, 1913 Abstergent · Ab·ster·gent · IPA /æbˈstɝ.d͡ʒn̩t/ a. n. 01 a. Serving to cleanse, detergent. 1. Serving to cleanse, detergent. 02 n. A substance used in cleansing; a detergent; as, soap is an abstergent. 1. A substance used in cleansing; a detergent; as, soap is an abstergent.