I. noun
also in·stal·ment in-ˈstȯl-mənt
Date: 1589
: installation 1
II. noun
also instalment
Etymology: alteration of earlier estallment payment by installment, from estall to arrange payments by installment, from Anglo-French estaler, from estal station, stall, division of a stage, of Germanic origin; akin to Old High German stal place, stall
Date: 1776
1. : one of the parts into which a debt is divided when payment is made at intervals
2.
a. : one of several parts (as of a publication) presented at intervals
b. : one part of a serial story
• installment adjective