15 U.S.C. § 694a

As used in this part— (1) The term “bid bond” means a bond conditioned upon the bidder on a contract entering into the contract, if he receives the award thereof, and furnishing the prescribed payment bond and performance bond. (2) The term “payment bond” means a bond conditioned upon the payment by the principal of money to persons under contract with him. (3) The term “performance bond” means a bond conditioned upon the completion by the principal of a contract in accordance with its terms. (4) The term “surety” means the person who (A) under the terms of a bid bond, undertakes to pay a sum of money to the obligee in the event the principal breaches the conditions of the bond, (B) under the terms of a performance bond, undertakes to incur the cost of fulfilling the terms of a contract in the event the principal breaches the conditions of the contract, (C) under the terms of a payment bond, undertakes to make payment to all persons supplying labor and material in the prosecution of the work provided for in the contract if the principal fails to make prompt payment, or (D) is an agent, independent agent, underwriter, or any other company or individual empowered to act on behalf of such person. (5) The term “obligee” means (A) in the case of a bid bond, the person requesting bids for the performance of a contract, or (B) in the case of a payment bond or performance bond, the person who has contracted with a principal for the completion of the contract and to whom the obligation of the surety runs in the event of a breach by the principal of the conditions of a payment bond or performance bond. (6) The term “principal” means (A) in the case of a bid bond, a person bidding for the award of a contract, or (B) the person primarily liable to complete a contract for the obligee, or to make payments to other persons in respect of such contract, and for whose performance of his obligation the surety is bound under the terms of a payment or performance bond. A principal may be a prime contractor or a subcontractor. (7) The term “prime contractor” means the person with whom the obligee has contracted to perform the contract. (8) The term “subcontractor” means a person who has contracted with a prime contractor or with another subcontractor to perform a contract. (9) Notwithstanding any other provision of law or any rule, regulation, or order of the Administration, for purpose of sections 694a, 694b, and 694c of this title the term “small business concern” means a business concern that meets the size standard for the primary industry in which such business concern, and the affiliates of such business concern, is engaged, as determined by the Administrator in accordance with the North American Industry Classification System.