Source : Webster's Revised Unabridged Dictionary (1913)

Diorite \Di"o*rite\, n. [Cf. F. diorite. See {Diorism}.] (Min.)
   An igneous, crystalline in structure, consisting essentially
   of a triclinic feldspar and hornblende. It includes part of
   what was called greenstone.

Source : WordNet®

diorite
     n : a granular crystalline intrusive rock