Entry 1 sense Webster, 1913 Synaptase · Syn·ap·tase · IPA 01 n. A ferment resembling diastase, found in bitter almonds. Cf. Amygdalin, and Emulsin. 1. A ferment resembling diastase, found in bitter almonds. Cf. Amygdalin, and Emulsin.(Chem.) See: Amygdalin, Emulsin