A casual phrase meaning "another time" or "some other time," used when deferring or declining an invitation or offer.
飲みに行かない？──ありがとう、今日は無理。じゃあ、また今度ね。
Want to go for a drink? — Thanks, I can't today. Well, maybe another time.
その話はまた今度詳しく聞かせてください。
Please tell me more about that another time.
予定が合わなかったらまた今度調整しましょう。
If the schedule doesn't work out, let's arrange it for another time.