Chasuble (Chas'-U-Ble). A sleeveless vestment or coat, devoid of buttons or other fastening, and provided with an opening in the center through which to pass the head. The chasuble is the principal garment worn by a priest when celebrating the mass or holy communion. It is held to represent the seamless coat of Christ, or charity symbolized by it. The material is usually rich stuff, silk brocade or velvet.