[ ad-uh-man-teen, -tin, -tahyn ]
See synonyms for adamantine on
  1. utterly unyielding or firm in attitude or opinion.

  2. too hard to cut, break, or pierce.

  1. like a diamond in luster.

Origin of adamantine

First recorded in 1200–1250; Middle English, from Latin adamantinus, from Greek adamántinos see adamant, -ine1

Words Nearby adamantine Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use adamantine in a sentence

  • Each bound to the other, through all the vicissitudes of life, in adamantine bonds of love and admiration!

  • The Jew is the dreamer in action, combining fluid imagination with adamantine purpose.

    Modernities | Horace Barnett Samuel
  • This electronic device Nick had stolen to operate the three ponderous triple-fold gates of adamantine, brass and iron.

    Satan and the Comrades | Ralph Bennitt
  • Moreover, the Hostel's point of view on the subject was as adamantine as it was universal.

    The War-Workers | E.M. Delafield
  • Watching us over the adamantine walls and all that kind of thing.

    The Wonderful Visit | Herbert George Wells

British Dictionary definitions for adamantine


/ (ˌædəˈmæntaɪn) /

  1. very hard; unbreakable or unyielding

  2. having the lustre of a diamond

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