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n. pl. gab·bros
A usually coarse-grained igneous rock composed chiefly of pyroxene and calcic plagioclase feldspar. Also called norite.

[Italian, perhaps from Latin glaber, bald, beardless.]

gab·bro′ic (gă-brō′ĭk), gab′broid′ (găb′roid′) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


gabbro-like, esp of a rock in the petrographic clan which contains the gabbro family
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
One of these, a medium-grained gabbroid, contains up to 3 cm long phenocrysts of plagioclase.
Unit G is composed of sparsely to moderately porphyritic basalt, with gabbroid xenoliths, plagioclase glomerocrysts and olivine microphenocrysts.
Pegmatoid and gabbroid layers in Jurassic Preakness and Hook Mountain basalts, Newark Basin, New Jersey.