忠心耿耿 [- - ɡěnɡ ɡěnɡ]keep [be] loyal to; be loyal and devoted (to); be most loyal; be staunch and steadfast; be true as steel; faithfully and conscientiously; infinitely loyal; most [firmly] faithful and true; perfect truth:
•¶ 鲁迅对人民忠心耿耿， 鞠躬尽瘁， 死而后已。 Lu Xun was loyal to the people, bending his back to the task until his dying day.