from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A gray, fine-grained volcanic rock, chiefly plagioclase and feldspar.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A class of fine-grained intermediate igneous rock, of volcanic origin, containing mostly plagioclase feldspar.
from the GNU version of the Collaborative International Dictionary of English
- n. An eruptive rock allied to trachyte, consisting essentially of a triclinic feldspar, with pyroxene, hornblende, or hypersthene.
from The Century Dictionary and Cyclopedia
- n. A volcanic rock of wide-spread occurrence, especially in the Cordilleran region of North America.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a dark grey volcanic rock
After the Andes .(American Heritage® Dictionary of the English Language, Fourth Edition)