难于启齿

很难开口。形容感到很难堪，很难为情。启齿：开口说出来。

不好意思说

羞口　讷怍　羞于启齿　说不出口
　因害羞而说不出口：碍口识羞　爱口识羞
不便说出口：碍口
　有话不便说：有口难言
　吃了亏不便说或不愿说：哑巴亏（吃哑巴亏）　哑叭亏
很难开口说出：难以启齿　难于启齿　难以出口　不便启口　有口难开　张不开口
有话但难说出口：棘喉
不知从何说起：无从说起　无从下口　无法下嘴
(不好说，不易说：难说)

难于启齿难以启齿nán yú qǐ chǐ

difficult to say it [when requesting unusual favours or asking for loans,etc]; find it difficult to bring the matter up; be too embarrassing to start to talk about sth;be too shy to speak out (/up); have a bone in one’s throat
❍ 你要我求他帮忙吗？ 我真～。Do you want me to ask him for help? I really find it difficult to bring the matter up.

难于启齿nán yú qǐ chǐ

见“难以启齿”。