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] 心里愤怒, 但迫于压力嘴上不敢明说

早对这条地头蛇恨之入骨, 只是敢怒不敢言