to be duplicated; to be repeated
to overlap; to fall together (of dates, etc.); to coincide
to repeat (a failed course, school year, etc.)
《baseball》to make a double play
《sports》to make a double fault (in tennis)
会議の時間がだぶった。
The meeting times overlapped.
同じ課題が二つだぶっていた。
The same assignment was duplicated twice.
予定がだぶると困るから先に確認しておこう。
Confirm in advance since it's a problem if schedules overlap.