This is the 4809th most frequent Japanese word.
油断
Negligence or carelessness.
The word '油断' here implies carelessness or a lack of alertness, leading to negligence in preparation.
彼は試験前に油断して遊んでしまった。
He was careless and played around before the exam.
In this sentence, '油断' refers to being unguarded, which resulted in being taken advantage of.
油断の隙を突かれてしまった。
We were caught off guard due to negligence.
Here, '油断' is used to warn against inattentiveness or a relaxed approach that might jeopardize success.