• (n.) A step or raised shelf, as above a sideboard or altar. Cf. Superaltar, and Gradin.
Gra·di'no noun ; plural Gradinos . [ Italian ] (Architecture) A step or raised shelf, as above a sideboard or altar. Confer Superaltar , and Gradin . 
In architecture a gradino is a step or raised shelf, as above a sideboard or altar.