saponaceous

Saponaceous is a New Latin borrowing by scientists that is based on sapo, the Latin word for "soap." It describes natural substances, like aloe gel or some plant roots, used in making soap or having the properties of soap. It also describes things that feel or appear soapy-for example, some shales and clays, mica, and certain chemical preparations. In the 19th century, saponaceous began to be used for people having a slippery, evasive, or elusive character. One famous example is the elocutionist Bishop Wilberforce whom British politician Benjamin Disraeli described as "unctuous, oleaginous, saponaceous." In The Devil's Dictionary, author Ambrose Bierce uses Disraeli's quote to illustrate the word oleaginous, noting that "the good prelate was ever afterward known as Soapy Sam."