formal
the word or phrase that exactly describes what you want to say.
I'm searching for the mot juste to describe him. Unusual, I think, is the best way of saying it.
英语词组固定搭配大全包含18674条英汉双解词组,基本涵盖了全部常用英文词组、短语的翻译及用法,是英语学习的有利工具。