a red letter day a pleasantly memorable, fortunate, or happy day.
☞ In Church calendars, a saint's day or church festival was traditionally distinguished by being written in red letters.
英语词组固定搭配大全包含15956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。