予約
よやく · yoyaku · JLPT N4 · noun
reservation
📅 予約 = beforehand (予) + promise (約): a promise made in advance
予 means in advance, as in 予定 (plan) and 予報 (forecast). 約 means promise, as in 約束 (promise). A reservation is literally an advance promise: you commit now to a table, room or seat you will use later.