›COMMERCE, FINANCEone of a number of parts into which an amount of money that is owed has been divided. Payments are made regularly until the total amount has been paid back: pay by/in instalmentsThe journal charges a yearly subscription of $1000, which readers can pay in instalments.pay by instalmentSmall shareholders were often given the opportunity to pay by instalment.pay/repay (the) instalmentsPlease contact our Help Line if you cannot pay the instalments.weekly/monthly/annual instalmentsto keep up (the) installmentsLouisiana got the final installment of its $10 billion in grant money in June.