[ mont-muh-ril-uh-nahyt ]
/ ˌmɒnt məˈrɪl əˌnaɪt /


any of a group of clay minerals characterized by the ability to expand when they absorb large quantities of water.

Origin of montmorillonite

1850–55; named after Montmorillon, France, where it was found; see -ite1
Also called smectite.

OTHER WORDS FROM montmorillonite

mont·mo·ril·lon·it·ic [mont-muh-ril-uh-nit-ik] /ˌmɒnt məˌrɪl əˈnɪt ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for montmorillonite

/ (ˌmɒntməˈrɪləˌnaɪt) /


a clay mineral consisting of hydrated aluminium silicate: an important component of bentonite

Word Origin for montmorillonite

C19: named after Montmorillon, French town where it was first found, + -ite 1
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