敢怒而不敢言　

◎ 敢怒而不敢言 gǎn nù ér bù gǎn yán

[be forced to keep one‘s resentment to oneself;hold back one‘s anger and dare not speak] 心里憤怒,但迫于壓力嘴上不敢明說

早對這條地頭蛇恨之入骨,只是敢怒不敢言