INSTALLMENT
installation, installing, installment, instalment
(noun) the act of installing something (as equipment); “the telephone installation took only a few minutes”
installment, instalment
(noun) a part of a published serial
episode, installment, instalment
(noun) a part of a broadcast serial
installment
(noun) a payment of part of a debt; usually paid at regular intervals
Source: WordNet® 3.1
Etymology 1
Noun
installment (plural installments) (American spelling)
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.
(banking, finance) One member of a series of portions of a debt or sum of money, which portions may or may not be equated (depending in part on whether the interest rate is fixed or variable), payment of which portions are serially exacted at regularly scheduled intervals toward satisfaction of the total. Payments of installments are generally mensual, quarterly, triannual, biannual, or annual.
(publishing, media) A part of a published or broadcast serial.
Usage notes
For this sense in the UK, the OED permits only the spelling instalment. Commonwealth usage varies.
Synonyms
• (portion of a debt)
• (part of a broadcast or published serial): episode, part
Etymology 2
Noun
installment (plural installments) (American spelling)
The act of installing; installation.
(obsolete) The seat in which one is placed.
Synonyms
• investiture, investment
• installation
Source: Wiktionary
In*stall"ment, n. Etym: [Written also instalment.]
1. The act of installing; installation.
Take oaths from all kings and magistrates at their installment, to do
impartial justice by law. Milton.
2. The seat in which one is placed. [Obs.]
The several chairs of order, look, you scour; . . . Each fair
installment, coat, and several crest With loyal blazon, evermore be
blest. Shak.
3. A portion of a debt, or sum of money, which is divided into
portions that are made payable at different times. Payment by
installment is payment by parts at different times, the amounts and
times being often definitely stipulated. Bouvier.
Source: Webster’s Unabridged Dictionary 1913 Edition