from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of various dark, granite-textured, crystalline rocks rich in plagioclase and having little quartz.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A grey intrusive igneous rock composed mostly of plagioclase feldspar, biotite, hornblende and/or pyroxene.
from the GNU version of the Collaborative International Dictionary of English
- n. An igneous, crystalline in structure, consisting essentially of a triclinic feldspar and hornblende. It includes part of what was called greenstone.
from The Century Dictionary and Cyclopedia
- n. The name given by Haüy to a rock included among those varieties which had before that time been generally designated by the name greenstone.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a granular crystalline intrusive rock
French, from Greek diorizein, to distinguish : dia-, apart, between; see dia- + horizein, to divide, limit; see horizon.(American Heritage® Dictionary of the English Language, Fourth Edition)