sine qua non

American  

[sahy-nee kwey non, kwah, sin-ey, si-ne kwah-nohn] / ˈsaɪ ni kweɪ ˈnɒn, kwɑ, ˈsɪn eɪ, ˈsɪ nɛ kwɑˈnoʊn /

noun

1. an indispensable condition, element, or factor; something essential.

   Her presence was the sine qua non of every social event.

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sine qua non British  

/ ˈsaɪnɪ kweɪ ˈnɒn /

noun

1. an essential condition or requirement

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sine qua non Cultural  

1. The essential, crucial, or indispensable ingredient without which something would be impossible: “Her leadership was the sine qua non of the organization's success.” From Latin, meaning “without which nothing.”

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sine qua non Idioms  

1. An essential element or condition, as in A perfect cake is the since qua non of a birthday party. This phrase is Latin for “without which not” and has been used in English since about 1600. It appears more in writing than in speech.

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Etymology

Origin of sine qua non

From Late Latin sine quā (causā) nōn “without which (thing) not”

Example Sentences

This is the sine qua non of self-defense.

From The Wall Street Journal • Mar. 12, 2026

But a first hostage deal “is the sine qua non of the administration’s larger regional deal,” said Martin S. Indyk, a former U.S. ambassador to Israel.

From New York Times • Jan. 25, 2024

For those actors who consider crying to be the sine qua non of their art, a sorrowful biography offers a distinct advantage in the Method acting sweepstakes.

From Los Angeles Times • Jan. 24, 2024

And in gourmet circles, nettles are the sine qua non of spring greens.

From Seattle Times • Mar. 18, 2023

It was as though he knew very well that in Lombard's past actions legality had not always been a sine qua non....

From "And Then There Were None" by Agatha Christie