Definition of "gabbro"

gabbro

/ˈɡabɹəʊ/

noun
countable and uncountable, plural gabbros
1. (petrology) Originally, a kind of serpentine; now generally a coarsely crystalline, igneous rock consisting of lamellar pyroxene and labradorite.
  Quotations
  It is known as gabbro and is thought to form the lower layer of the oceanic crust at about four kilometres depth and to comprise a layer up to six kilometres thick, making it one of the most abundant, if least recognisable, materials on earth.
  2004, Richard Fortey, The Earth, Folio Society, published 2011, page 59
  Against the dark Ordovician gabbro, the black volcanic base, Rhynie is a streak of technicolour.
  2022, Thomas Halliday, Otherlands, Penguin, published 2023, page 205