azo

n. [ Azo- + benzene. ] (Chem.) A substance (C6H5.N2.C6H5) derived from nitrobenzene, forming orange red crystals which are easily fusible. [ 1913 Webster ]

n. [ Sp. See Azoth. ] Lit.: Quicksilver; hence: pl. (Mining) Silver ores suitable for treatment by amalgamation with mercury. [ Sp. Amer. ] [ Webster 1913 Suppl. ]

a. [ Gr. 'a priv. + &unr_; life, from &unr_; to live. ] Destitute of any vestige of organic life, or at least of animal life; anterior to the existence of animal life; formed when there was no animal life on the globe; as, the azoic. rocks. [ 1913 Webster ]

Azoic age (Geol.), the age preceding the existence of animal life, or anterior to the paleozoic tome. Azoic is also used as a noun, age being understood. See Archæan, and Eozoic. [ 1913 Webster ]

n. [ From Azote. ] (Org. Chem.) Any of a large class of compounds characterized by a five-membered ring which contains an atom of nitrogen and at least one other noncarbon atom (nitrogen, oxygen, sulphur). The prefixes furo-, thio, and pyrro- are used to distinguish three subclasses of azoles, which may be regarded as derived respectively from furfuran, thiophene, and pyrrol by replacement of the CH group by nitrogen; as, furo-monazole. Names exactly analogous to those for the azines are also used; as, oxazole, diazole, etc. [ Webster 1913 Suppl. ]

a. [ Azo- + oleic. ] (Chem.) Pertaining to an acid produced by treating oleic with nitric acid. [ R. ] [ 1913 Webster ]

n. a genus of ferns, someties placed in its own family Azollaceae.
Syn. -- genus Azolla. [ WordNet 1.5 ]

n. a family designation used in some classifications for the genus Azolla.
Syn. -- family Azollaceae. [ WordNet 1.5 ]

adj. not divided into zones; -- opposite of zonal. azonal heating [ WordNet 1.5 ]