1911 Encyclopædia Britannica/Instalment

INSTALMENT (for earlier stallment or estallment, from Fr. estaler, to fix, arrange; the change is probably due to the influence of the verb “install”), the payment of a sum of money at stated intervals and in fixed portions instead of in a lump sum; hence the sums of money as they fall due at the periods agreed upon. For the system of purchase by deferred payments or instalments see Hire-Purchase Agreement.