installment

n.
  1. The act of installing; installation.
  2. The seat in which one is placed.
  3. A portion of a debt, or sum of money, which is divided into portions that are made payable at different times; that portion of a debt payed back in any one payment; as, the next installment is due January first. Payment by installment is payment by parts at different times, the amounts and times being often definitely stipulated.
  4. a part of a broadcast serial.
  5. a part of a published serial.