Being completely prepared; everything is ready and in order.
引っ越しは準備万端で、あとは荷物を運ぶだけだ。
The move is all set — all that's left is to carry the boxes.
会議の資料は準備万端なので、安心して参加してください。
The meeting materials are fully prepared, so please join with confidence.
明日の遠足のために、服や弁当を準備万端にしておこう。
Let's get our clothes and lunch completely ready for tomorrow's excursion.