[Gr. emplastron]

1. A material, usually plaster of Paris, that is applied to a part and allowed to harden in order to immobilize the part or to make an impression. In many settings, plaster of Paris has been replaced with synthetic cast materials, such as fiberglass.
2. A topical preparation in which the constituents are formed into a tenacious mass of substance harder than an ointment and spread upon muslin, linen, skin, or paper.