1610s, from Latin detergentem (nominative detergens), present participle of detergere "to wipe away, cleanse," from de- "off, away" (see de-) + tergere "to rub, polish, wipe." Originally a medical term, application to "chemical cleansing product" is from 1938.
"detergent substance," 1670s, from detergent (adj.).
detergent de·ter·gent (dĭ-tûr'jənt)
A cleansing substance that acts similarly to soap but is made from chemical compounds rather than fats and lye. adj.
Having cleansing power.
A cleaning agent that increases the ability of water to penetrate fabric and break down greases and dirt. Detergents act like soap but, unlike soaps, they are derived from organic acids rather than fatty acids. Their molecules surround particles of grease and dirt, allowing them to be carried away. Compare soap.