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in advance; beforehand; previously; ahead of time
前以て連絡してもらえると助かります。
It'd be helpful if I could have you let me know in advance.
前以て準備しておけば慌てなくて済む。
If you prepare in advance, you won't have to panic.
前以て予約しないと入れない店だ。
It's a restaurant you can't get into without a reservation.