韬晦

tāohuì

(1) [refrain from revealing one's ambitions and put others off the track]∶韬, 韬光; 晦, 晦迹。 韬晦, 即收敛锋芒, 隐藏不露

愈事韬晦, 群居游处, 赤尝有言。 --《唐书·宣宗纪》

(2) [dark; gloomy]∶阴暗无光; 阴晦