from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An absorbent aluminum silicate clay formed from volcanic ash and used in various adhesives, cements, and ceramic fillers.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of several impure clay minerals consisting mostly of montmorillonite.
- n. A porous clay formed by the decomposition of volcanic ash that swells 5 to 6 times its original volume in the presence of water.
from the GNU version of the Collaborative International Dictionary of English
- n. an absorbent aluminum silicate clay formed from volcanic ash.
from The Century Dictionary and Cyclopedia
- n. A variety of clay occurring extensively in the Fort Benton strata of the Cretaceous of Wyoming.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an absorbent aluminum silicate clay formed from volcanic ash
After Benton Formation (formerly Fort Benton Formation) of the Rock Creek district in eastern Wyoming.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Benton + -ite, after the place it was first mined: Fort Benton, Montana. (Wiktionary)