saponifier|səˈpɒnɪfaɪə(r)| [f. next + -er1.] 1. An apparatus for isolating glycerine and the fatty acids by saponification. 188.Sci.Amer. Sup. 2562 (Knight). 2. An alkali used in saponification. 1872Crookes Wagner's Handbk.Chem.Technol. 242 Natrona refined saponifier.