1to agree on sth (after discussion)
2to conclude a bargain
3to arrange
4to promise
5to stipulate
6to make an appointment
7stipulated (time, amount, quality etc)
8an arrangement
9a deal
10appointment
11undertaking
12commitment
13understanding
14engagement
15stipulation
Example
dàng当wǒ我wàng jì忘记yuē dìng约定shí时，tā他shí fēn十分fèn nù愤怒。
当我忘记约定时，他十分愤怒。
He was very angry with me when I forgot the appointment.