instalment

 
Pronunciation: /ɪnˈstɔːlm(ə)nt/
(US also installment)

noun

  • 1a sum of money due as one of several equal payments for something, spread over an agreed period of time: the first instalment of a grant for housing the purchase price is paid in instalments
  • 2any of several parts of something which are published, broadcast, or made public in sequence at intervals: filming the final instalment in his Vietnam trilogy
  • 3 [mass noun] the process of installing something; installation: instalment will begin early next year

Origin:

mid 18th century (denoting the arrangement of payment by instalments): alteration of obsolete estalment (probably by association with installation), from Anglo-Norman French estalement, from Old French estaler 'to fix'

Spelling help

Spell instalment with one l (the spelling installment is American).

Spelling rule

If a word ends in a double l, drop the last l when adding endings which begin with a consonant (here, install plus -ment): instalment.