The Collaborative International Dictionary of English v.0.48:

Azole \Az"ole\, 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.]