installmentnoun [ C ]
us/ɪnˈstɔl·mənt/one of a number of payments that you make over a period of time to pay for something that you can use while you are paying for it:
We paid for the car in monthly installments over two years.
An installment is also one of the parts of something, such as a show, that is experienced as part of a series over a period of time:
a TV miniseries with five installments