1an agreement or stipulation; a formal contract or arrangement, often used in commerce or finance.
売買の約定は両者の署名により成立した。
The sales agreement was concluded with the signatures of both parties.
約定した期限内に支払いが行われなかった。
The payment was not made within the agreed deadline.
証券取引では約定した時点で取引が確定する。
In securities trading, the transaction is finalized at the moment it is executed (the agreement is made).