What term describes a substance that is soapy or resembles soap?

The term "saponaceous" refers to a substance that has qualities characteristic of soap, including a slippery texture or the ability to create lather. This term is derived from "sapo," the Latin word for soap, indicative of its properties. It is often used in chemistry and biology to describe substances that behave similarly to soap or have a similar composition.

In contrast, the other terms do not relate to the properties of soap. "Sarapus" and "sicchsia" do not represent widely recognized words in the medical or scientific vocabulary, thereby lacking relevance. "Sequestration" refers to the act of isolating or removing something, particularly in a medical or legal context, and is not related to the soapy characteristics inherent to saponaceous substances. Thus, "saponaceous" is the most accurate term in this context.