Allier, a central department of France, part of the old province of Bourbonnais, bounded by Nievre, Saone-et-Loire, Puy-de-dome, Creuse, and Cher; area, 2,822 sq. m.; pop. in 1872, 390,812. It takes its name from the river Al-lier, which flows through its centre; the Cher, like the Allier a southern affluent of the Loire, flows through the western part of the department, and the Loire waters its eastern border. The surface is undulating, and the soil generally fertile, yielding much grain and wine. Coal and minerals of various kinds abound; and there are celebrated mineral springs. The department is divided into the arrondisseinents of Moulins, La Palisse, Gannat, and Montlucon. Capital, Moulins.