{ } a. [ Gr. &unr_; disjunctive, fr. &unr_; to disjoin; dia` through, asunder + &unr_; to join, yoke. ] (Anc. Mus.) Disjoining two fourths; as, the diazeutic tone, which, like that from F to G in modern music, lay between two fourths, and, being joined to either, made a fifth. [ Obs. ] [ 1913 Webster ]

[ Pref. di- + azo- ] (Chem.) A combining form (also used adjectively), meaning pertaining to, or derived from, a series of compounds containing a radical of two nitrogen atoms, united usually to an aromatic radical; as, diazo-benzene, C6H5.N2.OH. [ 1913 Webster ]

☞ Diazo compounds are in general unstable, but are of great importance in recent organic chemistry. They are obtained by a partial reduction of the salts of certain amido compounds. [ 1913 Webster ]

Diazo reactions (Chem.), a series of reactions whereby diazo compounds are employed in substitution. These reactions are of great importance in organic chemistry. [ 1913 Webster ]

v. t. (Chem.) To subject to such reactions or processes that diazo compounds, or their derivatives, shall be produced by chemical exchange or substitution. [ 1913 Webster ]