sine qua non
- an indispensable condition, element, or factor; something essential: Her presence was the sine qua non of every social event.
Origin of sine qua non
causa sine qua non
- an indispensable condition; requisite.
Origin of causa sine qua non
sine qua non
- an essential condition or requirement
Word Origin
Word Origin and History for sine qua non
"an indispensable condition," Latin, literally "without which not," from sine "without" (see sans) + qua ablative fem. singular of qui "which" (see who) + non "not" (see non-). Feminine to agree with implied causa. The Latin phrase is common in Scholastic use. Sometimes a masculine form, sine quo non, is used when a person is intended. Proper plural is sine quibus non.
sine qua non
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.”
Idioms and Phrases with sine qua non
sine qua non
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.