A Cornish game hen, also sometimes called a poussin, cornish hen, Rock Cornish hen, or simply Rock Cornish, is a young chicken sold whole. Despite the name, it is not game, but is a chicken, developed in the late 1950s in California by a French immigrant. The Cornish part of the name, it derives from the most common bird grown and sold in this manner, a cross of the Cornish and Plymouth Rock breeds.
The U.S. Department of Agriculture requires that all chickens sold as Cornish game hens be no more than 2 pounds in ready-to-cook weight and no more than 5 to 6 weeks old at slaughter. As is common in the poultry industry, store-bought hens may be either male or female specimens, despite the common usage of the word "hen" typically denoting a female.