The Collaborative International Dictionary
                    tetraboric
                    
                        
                
                                                                    Pyroboric \Pyr`o*bo"ric\, a. [Pyro- + boric.] (Chem.) Pertaining to derived from, or designating, an acid, H2B4O7 (called also tetraboric acid), which is the acid ingredient of ordinary borax, and is obtained by heating boric acid.