From Middle High German borste, from Old High German borsta, bursta, from Proto-West Germanic *borstā, *burstā, an early stem variant of *bursti, whence German Bürste (“brush”), which compare. Both words originally meant “bristle”, the semantic distinction is a later development. Immediately cognate with Old Saxon bursta (also *borsta as evidenced by Westphalian Boarste, Buoste).