骨鯁

fish bone / bone stuck in the throat / sth one feels obliged to speak out about / candid speaker

bone

to choke on a piece of food / (literary) a fish bone lodged in one's throat

fish bone stuck in one's throat (idiom); fig. to feel obliged to speak out candidly / sth on one's mind

lit. fish bone of a minister (idiom); fig. person one can rely on for candid criticism