From Longman Business Dictionary
suppliersup·pli·er /səˈplaɪə-ər/ noun [countableC]COMMERCE a company that provides a particular type of productsupplier ofMicrosoft is the world’s largest supplier of PC software.
With California’s orange crop halved, local suppliers have had to find alternative sources.
What the retailer needs is a larger supplier base in order to be more competitive.
→ first-tier supplier → preferred supplier → second-tier supplier