ad·​a·​man·​tine | \ˌa-də-ˈman-ˌtēn, -ˌtīn, -ˈman-tᵊn\

Definition of adamantine 

1 : made of or having the quality of adamant

2 : rigidly firm : unyielding adamantine discipline

3 : resembling the diamond in hardness or luster

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Did You Know?

The Greek and Latin word for the hardest imaginable substance, whether applied to a legendary stone or an actual substance, such as diamond, was "adamas." Latin poets used the term figuratively for things lasting, firm, or unbending, and the adjective "adamantinus" was used in similar contexts. The English noun "adamant" (meaning "an unbreakable or extremely hard substance"), as well as the adjective "adamant" (meaning "inflexible" or "unyielding"), came from "adamas." "Adamantine," which has such figurative uses as "rigid," "firm," and "unyielding," came from "adamantinus." "Adamas" is actually the source of "diamond" as well. "Diamas," the Latin term for diamond, was an alteration of "adamas."

Examples of adamantine in a Sentence

the adamantine opposition of his parents to his marriage to a girl from a poor family

Recent Examples on the Web

But not even adamantine willpower could overcome the exhaustion that Rihanna was feeling in that moment. Chioma Nnadi, Vogue, "Rihanna on Body Image, Turning 30, and Staying Real—No Matter What," 3 May 2018 But Navalny, with adamantine determination and a canny use of social media, has spread his anti-corruption campaign deep into the provinces. Washington Post, "Alternatives to Putin a mixed bag as Russian election looms," 25 Oct. 2017 Harrison’s music traverses a huge stylistic range, from adamantine dissonance to melodies of homespun sweetness. Alex Ross, The New Yorker, "New York Celebrates a Composer Who Left Town," 14 Apr. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'adamantine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of adamantine

13th century, in the meaning defined at sense 1

History and Etymology for adamantine

Middle English, borrowed from Anglo-French, borrowed from Latin adamantinus, borrowed from Greek adamántinos, derivative of adamant-, adámas adamant entry 2

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The first known use of adamantine was in the 13th century

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More Definitions for adamantine


ad·​a·​man·​tine | \ˌad-ə-ˈman-ˌtēn, -ˌtīn, -ˈmant-ᵊn \

Medical Definition of adamantine 

: characterized by extreme hardness or luster

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to clear from alleged fault or guilt

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