from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A metamorphic rock, intermediate between shale and slate, that does not possess true slaty cleavage.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fine-grained sedimentary rock, intermediate between shale and slate, sometimes used as a building material
from the GNU version of the Collaborative International Dictionary of English
- n. Argillaceous schist or slate; clay slate. Its colors is bluish or blackish gray, sometimes greenish gray, brownish red, etc.
from The Century Dictionary and Cyclopedia
- n. Argillaceous schist or slate; clay slate (which see, under clay).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a sedimentary rock differing from shale in being bound by silica and from slate in having no slate cleavages
Latin argilla, argil; see argil + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)