This is the 2509th most frequent Chinese word.
松懈
"松懈" means "to relax, slacken, or become less vigilant."
In this sentence, '松懈' is used to describe a decrease in diligence or strictness in one's studies after a certain period of exertion.
考试结束后,他开始在学习上松懈下来。
After the exam ended, he started to relax in his studies.
Here, '松懈' conveys the concept of remaining vigilant and avoiding any relaxation when dealing with challenges.
面对困难,我们不能有丝毫的松懈。
In the face of difficulties, we cannot have the slightest relaxation.
This usage of '松懈' emphasizes the prohibition of laxity or slackness in work attitude as a professional requirement.