1.
to neglect; to be negligent
To fail to do something that should be done, often due to laziness or carelessness.
勉強を怠ると、成績が下がる。
If you neglect your studies, your grades will drop.
安全確認を怠ってはいけない。
You must not neglect safety checks.
[Note: 怠っては + いけない = must not neglect]
努力を怠らなければ、必ず成功する。
If you don't slack off on your efforts, you will surely succeed.
Negative conditional form
2.
to be lazy about; to slack off on
To not put sufficient effort into a duty or task.
練習を怠っていたので、試合で負けた。
I had been slacking off on practice, so I lost the game.
掃除を怠っていたら、部屋が汚くなった。
I was lazy about cleaning, and the room got dirty.
日頃の運動を怠ると、体力が落ちる。
If you slack off on daily exercise, your stamina declines.
怠る is a transitive verb (他動詞). It takes を to mark what is being neglected.
ASPECT ({ている}):
The ている form indicates an ongoing state of neglect (義務を怠っている = 'is neglecting one's duty').
PARTICLE PATTERNS:
- [duty/task]を怠る (neglect ~)
COMMON PATTERNS:
- 義務を怠る (neglect a duty)
- 努力を怠る (slack off on effort)
- 注意を怠る (be negligent in attention)
- 健康管理を怠る (neglect health management)
This verb has a somewhat formal tone and is often used in written contexts. The related noun is 怠慢 (negligence).