The Collaborative International Dictionary
saponule
Saponul \Sap"o*nul\, n. [F. saponule, fr. L. sapo, -onis, soap.] (Old Chem.) A soapy mixture obtained by treating an essential oil with an alkali; hence, any similar compound of an essential oil.
Wiktionary
saponule
n. (context chemistry obsolete English) A soapy mixture obtained by treating an essential oil with an alkali; hence, any similar compound of an essential oil.