What do a.m. and p.m. stand for?


[ben-tn-ahyt] /ˈbɛn tnˌaɪt/
noun, Mineralogy
a clay formed by the decomposition of volcanic ash, having the ability to absorb large quantities of water and to expand to several times its normal volume.
Origin of bentonite
1895-1900; named after Fort Benton, Montana; see -ite1
Related forms
[ben-tn-it-ik] /ˌbɛn tnˈɪt ɪk/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for bentonite
  • bentonite slurry, a gelatinous blend of clay and water, was pumped into the growing hole to prevent the sides from caving in.
  • bentonite in large concentrations is sticky, used for drilling muds on oil rigs and also for forming clay molds for metal casting.
  • The mud is made from a variety of materials such as the clay mineral bentonite.
  • bentonite is an extremely absorbent, granular clay formed from volcanic ash.
  • Most types of bentonite swell when they absorb water.
  • bentonite clay is often recommended to help seal porous pond bottom soils.
  • Calcium bentonite calcium bentonite is a useful adsorbent of ions in solution.
British Dictionary definitions for bentonite


a valuable clay, formed by the decomposition of volcanic ash, that swells as it absorbs water: used as a filler in the building, paper, and pharmaceutical industries
Word Origin
C19: from Fort Benton, Montana, USA, where found, + -ite1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source

Word of the Day

Difficulty index for bentonite

Some English speakers likely know this word

Word Value for bentonite

Scrabble Words With Friends

Nearby words for bentonite