supplysupplysupplies1noun (pluralsupplies)a store or an amount of something that you need: Food supplies were dropped by helicopter. The water supply was cut off.supplysupplysuppliessuppliedsupplying2verb (supplies, supplying, supplied/, has supplied)to give or sell something that somebody needs: The school supplies us with books.The lake supplies water to thousands of homes.▶ suppliersuppliersuppliersnoun: We are the region's biggest supplier of computer equipment.