detergent (adj.) Look up detergent at Dictionary.com
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 (n.) Look up detergent at Dictionary.com
"detergent substance," 1670s, from detergent (adj.).