One who enters into a contract this term is usually applied to persons who undertake to do public work, or the work for a company or corporation on a large scale, at a certain fixed price, or to furnish goods to another at a fixed or ascertained price.
Law Dictionary – Alternative Legal Definition
This term is strictly applicable to any person who enters into a contract, (Kent v. Railroad Co., 12 N. Y. 628>> but is commonly reserved to designate one who, for a fixed price, undertakes to procure the performance of works on a large scale, or the furnishing of goods in large quantities, whether for the public or a company or individual.