Webster’s Revised Unabridged Dictionary · 1913
Saponaceous
Sap′o·na′ceous, a. [L. sapo, -onis, soap, of Teutonic origin, and akin to E. soap. See Soap.] Resembling soap; having the qualities of soap; soapy.
☞ Saponaceous bodies are compounds of an acid and a base, and are in reality a kind of salt.