from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A variety of diorite consisting chiefly of feldspar.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A phaneritic, intrusive igneous rock characterized by a predominance of plagioclase feldspar.
from the GNU version of the Collaborative International Dictionary of English
- n. A granular igneous rock composed almost exclusively of a soda-lime feldspar, usually labradorite.
from The Century Dictionary and Cyclopedia
- n. In petrography, a granular or gneissoid igneous rock of eastern Canada, consisting chiefly of the plagioclase feldspar, labradorite.
French anorthose, a kind of feldspar (Greek an-, not; see a-1 + Greek orthos, straight) + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)