expression, godan verb (-ru)
become late; fall behind; lag; pass (of time)
Used when something ends up later than expected or when time passes. Often implies a delay or that a scheduled time has already gone by.
気がついたらもうこんな時間。ずいぶん後になったね。
Before I knew it, it was already this late. Time has really passed, hasn't it?
The meeting started late, and everyone was irritated.
返事が後になってしまい、申し訳ありません。
I'm sorry my reply is late.