if you do something without a second thought, you do it without thinking about whether or not you should.
She doesn't worry about money - she'll spend a hundred pounds on a dress without a second thought.
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。