Meaning

noun a small inflamed elevation of the skin; a pustule or papule; common symptom in acne

originEarly Modern English pimple, pumple, from Middle English pymple, pympyl, of uncertain origin but probably a nasalized variant of Old English *pipel, *pypel, from Old English piplian, pyplian (“to break out in pimples, show eruptions”), probably related to Latin papula (“pimple, pustule”) (from Proto-Indo-European *pap- (“pock mark, nipple”)). Akin to Old English pipliġende (“having shingles”).

Etymology from Wiktionary, CC BY-SA 3.0