When the word detergent was first used at the start of the seventeenth century, it was an adjective meaning "cleansing" or "purging", and around the 1670s it also became a noun referring to cleaning agent. This was originally meant in a medical sense, but it started being used for household cleaning products in the 1930s. The word comes from Latin detergentem, the accusative of the present participle of the verb detergere, meaning "wipe away". That contains the prefix de-, meaning "off" or "away" (probably ultimately of Etruscan origin), and the verb tergere, "to wipe". Tergere, which is also the source of the word terse (which evolved from connotations of cleanliness to conciseness), is listed in several places as being of uncertain origin, but there's alsoa. theory that it may have developed from the Proto-Indo-European reconstruction terh, meaning "to rub".
Hello! I'm Adam Aleksic. This year, I graduated from Harvard University with a degree in Government and Linguistics. There, I co-founded the Harvard Undergraduate Linguistics Society and wrote a thesis on Serbo-Croatian language policy, magna cum laude. In addition to etymology, I also really enjoy philosophy, trivia, vexillology, geography, board games, conlanging, art history, and law.