[ feld-spa-thoid, fel- ]
/ ˈfɛld spæˌθɔɪd, ˈfɛl- /


Also feld·spath·oi·dal. of or relating to a group of minerals similar in chemical composition to certain feldspars except for a lower silica content.


a mineral of this group, as nepheline.

Origin of feldspathoid

1895–1900; < German Feldspath (see feldspar) + -oid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for feldspathoid

/ (ˈfɛldspəˌθɔɪd) /


any of a group of rock-forming minerals, such as leucite and sodalite, that are similar to feldspars but contain less silica
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

Science definitions for feldspathoid

[ fĕld-spăthoid′, fĕl- ]

Any of a group of relatively rare minerals that are chemically very similar to feldspars, but have too little silica to qualify as feldspars. Feldspathoids occur in igneous rocks with little or no silica.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.