廢寢忘食，漢語成語，字面意思是顧不能睡覺，忘記了吃飯。形容很勤奮專心。可以翻譯為（be so absorbed and occupied as to）forget all about eating and sleeping或skip ones meals and sleep。
例句：
廢寢忘食地工作
Devote oneself heart and soul to ones work
有時她甚至廢寢忘食，一直工作到深夜。
Sometimes she even forgets to eat and rest and works1 until late night.