adamantine

adjective

ad·a·man·tine ˌa-də-ˈman-ˌtēn

-ˌtīn,

-ˈman-tᵊn

Synonyms of adamantine

: made of or having the quality of adamant

: rigidly firm : unyielding

adamantine discipline

: resembling the diamond in hardness or luster

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 applied in similar contexts. The English noun adamant (meaning "an unbreakable or extremely hard substance") as well as the adjective adamant ("inflexible" or "unyielding") came from adamas. Adamantine, however—which has such figurative uses as "rigid," "firm," and "unyielding"—came from adamantinus. Adamas is also the source of diamond. Diamas, the Latin term for diamond, is 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

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Still, Naz, whose solitary ways confuse his family, very much wishes that Aziza wasn’t meeting his adamantine mother, Claudine (LaTanya Richardson Jackson), or his famous father, or his ex-state-senator older brother, Junior (Glenn Davis), recently incarcerated for embezzling campaign funds. —Helen Shaw, The New Yorker, 20 Mar. 2025 Image My first collision with the adamantine wall of Vivamayr house rules coincided with my arrival. —Caity Weaver, New York Times, 25 Jan. 2025

Word History

Etymology

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

First Known Use

13th century, in the meaning defined at sense 1

Time Traveler

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

See more words from the same century