To collect, gather, or accumulate (things, money, fatigue, water, etc.) in one place or over time. Often written in kana but can be written as 溜まる.
仕事の疲れがたまって、週末はずっと寝ていた。
I had built up work fatigue and slept all weekend.
毎月少しずつ貯金がたまってきた。
My savings have been accumulating little by little each month.
台所の排水口にゴミがたまって水が流れにくくなった。
Trash had accumulated in the kitchen drain and the water started to drain poorly.
怒りがたまると、つい大きな声を出してしまうことがある。
When anger accumulates, I sometimes end up raising my voice.