Fulminuric adj. (Chem.) Pertaining to fulminic and cyanuric acids, and designating an acid so called. Fulminuric acid (Chem.), a white, crystalline, explosive substance, H3C3N3O3, forming well known salts, and obtained from the fulminates. It is isomeric with cyanuric acid, and hence is also called isocyanuric acid.