installment

noun5

1. •
   One of a series of parts, whether equal or unequal to the other parts of the series, of a given entity or a given process, which part presents or is presented at a particular scheduled interval.

   • Not to give rise to suspicion, I drank when they were looking, and when able to do it unperceived, I quietly deposited the contents, by installments, under the table. — 1861
2. •
   Any of a series of portions of a debt or sum of money, which portions may or may not be equal in amount (depending in part on whether the interest rate is fixed or variable), and payment of which takes place at regular intervals toward satisfaction of the total. Payments are generally mensual, quarterly, triannual, biannual, or annual.
3. •
   A part of a published or broadcast serial.

   • With The Two Towers, the new installment of the Lord of the Rings trilogy, about to storm the box office, we are seeing what might be called the enchanting of America. — 2010
4. •
   The act of installing; installation.

   • Take oaths from all kings and magistrates at their installment, to do impartial justice by law. — 1649
5. •
   (no longer used) The seat in which one is placed.

   • Each faire Instalment, Coate, and seu’rall Crest, With loyall Blazon, euermore be blest. — 1597