The Collaborative International Dictionary of English v.0.48:
Nauseant \Nau"se*ant\, n. [L. nauseans, p. pr. Of nauseare.] (Med.) A substance which produces nausea; an emetic. [1913 Webster]WordNet (r) 3.0 (2006):
nauseant n 1: a medicine that induces nausea and vomiting [syn: emetic, vomit, vomitive, nauseant]