To beat someone or something with a whip or stick as punishment, or to criticize harshly; also slang for selling or promoting something persistently.
Possibly from Portuguese 'flauta' (flute) mistaken for related to 'flail,' or from Latin 'flagellum.' The word entered English in the 17th century with the meaning of 'to whip,' later becoming figurative.
In British slang, 'flogging a dead horse' means keep trying when it's hopeless—the phrase comes from the cruel but literal practice of whipping exhausted animals, showing how slang can preserve dark history!
Complete word intelligence in one call. Free tier — 50 lookups/day.