Vitreous/ˈvɪtriəs/ Definition 1 of 2Pro Tip 1/3Material Texture Describes the hard, smooth texture of something, similar to glass. The sculpture had a vitreous surface, reflecting the light. Pro Tip 2/3Not Always Transparent Even though it's glass-like, 'vitreous' doesn't mean transparent. The vase was a vitreous blue, opaque and glossy. Pro Tip 3/3Artistic Reference Commonly used in art and ceramics, referring to a glassy coating or finish. The potter explained the process of applying a vitreous glaze.