All at once; together; in one go — doing or handling multiple items collectively rather than separately.
請求書はまとめて送ってください。
Please send the invoices all together.
買い物はまとめて支払ったほうが手間が省ける。
It's less hassle to pay for the shopping all at once.
週末にまとめて掃除しておくと平日が楽になる。
If you clean everything at once on the weekend, weekdays become easier.