1A reserve or spare item/person kept aside as a backup (e.g., spare part, substitute player).
試合には主力に加えて控えの選手も登録されている。
In the match, substitute players are registered in addition to the starters.
予備部品は必ず倉庫に控えを置いておくこと。
Always keep spare parts in the warehouse.
カメラのバッテリーは念のため控えを持って行った。
I brought a spare camera battery just in case.
2A note or memorandum kept as a record to remember something or document a transaction.
支払いの控えを必ず受け取ってください。
Please be sure to receive a receipt of payment.
面談の要点を控えに書き留めた。
I jotted down the key points of the interview in my notes.
3A duplicate or copy (e.g., ticket stub, receipt copy) kept as proof or record.
コンサートのチケットの控えは失くさないでください。
Please don't lose the ticket stub for the concert.
領収書の控えを経費精算に添付した。
I attached the receipt copy to the expense report.
4Being in a state of waiting for one's turn or for an upcoming event; often used in expressions like '〜を控え' (with ... approaching).
入試を控え、受験生たちはラストスパートをかけている。
With the entrance exams approaching, the examinees are making a final push.
結婚式を控え、二人は忙しく準備を進めている。
With the wedding looming, the couple is busy making preparations.