SURD Synonyms: 127 Similar and Opposite Words

surd

adjective

Definition of surd

as in irrational

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Recent Examples of Synonyms for surd

Adjective

But the question remained unsolved for polygons with irrational angles.

— Sam Macdonald, Scientific American, 14 Aug. 2026
As a result, the argument goes, today's spending is irrational because the hardware would need to be replaced too frequently to generate an attractive return on investment, known as ROI.

— , CNBC, 12 Aug. 2026

Definition of irrational

Adjective

Lambasting Lambert for the performance is illogical, but so is placing so much importance on one player.

— Chandler Rome, New York Times, 21 Aug. 2026
But Musgrove said Clancy lost a lot of weight during that time, struggled with her memory and became paranoid about illogical things.

— Nicki Brown, CNN Money, 21 Aug. 2026

Definition of illogical

Adjective

But in each event—in the living act, the undoubted deed—there, some unknown but still reasoning thing puts forth the mouldings of its features from behind the unreasoning mask.

— Literary Hub, Literary Hub, 6 July 2026
Roosevelt surely understood that nameless, unreasoning, unjustified fear cannot be eradicated.

— New York Times, New York Times, 9 June 2026

Definition of unreasoning

Adjective

At the outset of this chatty novel, the protagonist, Caroline, who was recently ghosted by a thoughtless man, has had a story published in this magazine.

— The New Yorker, New Yorker, 10 Aug. 2026
That self-deprecating description opens Tony, writer-director Matt Johnson’s movie about the one crazy summer that changed a thoughtless young lout’s life; for good measure, the quote does double duty as the tagline on the film’s poster.

— David Fear, Rolling Stone, 5 Aug. 2026

Definition of thoughtless

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surcoats

surd

sure

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“Surd.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/surd. Accessed 1 Sep. 2026.

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Synonyms of surd

adjective

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