骨鯁之臣

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

bone

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

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

(possessive particle, literary equivalent of 的[de5]) / him / her / it

surname Chen

state official or subject in dynastic China / I, your servant (used in addressing the sovereign) / Kangxi radical 131