party of the first part
n. reference in a written contract to identify one of the people entering into the agreement. The agreement would read "Mary McConnell (hereinafter called The Party of the First Part)." Better practice is to identify the parties by a short form of their name ("hereinafter referred to as McConnell") or as Buyer, Seller, Owner, Trustee or some other useful identification. Name use aids in following and understanding the contract and avoids confusion with "the party of the second part," which identifies another party to the agreement.