adamantine

American  

[ad-uh-man-teen, -tin, -tahyn] / ˌæd əˈmæn tin, -tɪn, -taɪn /

adjective

1. utterly unyielding or firm in attitude or opinion.

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

3. like a diamond in luster.

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adamantine British  

/ ˌædəˈmæntaɪn /

adjective

1. very hard; unbreakable or unyielding

2. having the lustre of a diamond

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Etymology

Origin of adamantine

First recorded in 1200–1250; Middle English, from Latin adamantinus, from Greek adamántinos see adamant, -ine ¹

Explanation

Something adamantine is unbreakable. Adamantine is often used in a figurative way. If you’re bound by adamantine chains, get comfy because you’re not breaking free! When someone is adamant, the person won't budge or yield. Anything adamantine is pretty much unbreakable and invulnerable. Adamantine substances also tend to be bright and shiny like diamonds. When used figuratively, adamantine can describe something unbreakable, like the adamantine will of a marathon runner.

Example Sentences

Adamantine candles are the best, as they last twice as long, and do not melt and run down the sides like the parraffine or tallow candles.

From Harper's Round Table, May 28, 1895 by Various

How didst thou pass the Adamantine Gate; And into Spirit thy self insinuate?

From The History of the Devil As Well Ancient as Modern: In Two Parts by Defoe, Daniel

Adamantine as was the lichen-covered heap of granite, it was of far more mutable a quality than were the dispositions of those who had so stubbornly let it fall into decay.

From The Wall Between by Bassett, Sara Ware

The "Black Breech Ordnance Company" and the "Adamantine Ship Company" would soon find representatives in Parliament, if forty or fifty members would get the national custom for their rubbish.

From The English Constitution by Bagehot, Walter

Adamantine Bouille's look alters not; yet the word Halt is given: gladder moment he never saw.

From The French Revolution by Carlyle, Thomas