Definition of Venetian Plaster by Zingarelli and other great dictionaries

Stucco and modern term confusion

New Zingarelli 11th edition:

Stucco: from Longobard stuhhi "coating, plaster")
Stucco 1): mortar made by thick limestone and marble powder used to cover architectural frames to make them marble looking or to create decors, frames and so on.
Stucco 2): decorative relief, decoration, sculpture etc. made with stucco

Grande Enciclopedia - Geographic Institute De Agostini - Novara

Stucco: (XIII century, from german term stukki, piece)
Stucco 1): general name given to different mixture and plaster fit to fill holes, level surfaces, make relief decors. Specially a flakes and strong glue based on material fit to smooth surfaces which present holes or roughness, useful to make finishes and also for moulding and decorative relieves.
Stucco 2): ART. Stucco widely used since ancient times both as single plaster to cover walls and other architectural components and as supply to shape sculptures with reliefs, it is a mixture made by gypsum and marble powder (or sand), binded with water and different glues, which gives several facilities. Beside being cheaper this mixture is easy to work (very ductile and dries with air) and very resistant against atmospheric agents. Stucco is spreaded with spatula and point brushes and shaped also with hands or with stencil shapes in case of repetitive decoration. Sometime it is worked when already dried. Often it is hanged to the wall with metallic pins (in case of very overhanging characters) or with wooden trellis (repetitive decoration).

The Great UTET Encyclopedic Dictionary

Stucco: material used for decoration, a mixture made by gypsum or very tiny crushed marble, with limestone and pozzolana; spreaded over a perfectly smooth surface (stone or wood) it is a perfect set-up for following painting; as much it was used by classic architecture for pats to be done in polychromia; during Middle Age and Renaissance used for boards to be painted, during '700 for furniture, then lacquered; Stucco is often worked when wet moulding and shaping it with moulds or with hands, or even dried, sculpting it as if stone. So they make bas-relief sculpture and also all round, which since ancient time were widely used in exterior and interior design, for vaults, ceilings and walls.