n. The act of installing or giving possession of an office with the usual ceremonies or solemnities; installation.n. The seat in which one is installed.n. A partial payment on account of a debt due; one of several parts into which a debt is divided for payment at different times: as, to pay for a purchase by or in instalments; to sell goods on instalments (that is, on condition of taking pay by instalments, sometimes with a stipulation that in default of payment of an instalment the seller may retake the goods and keep by way of forfeiture what has been paid).n. A part of anything produced or furnished in advance of the remainder; one of a number of parts produced at different times: as, to publish a novel or to deliver stores in or by instalments.