Definition of sine qua non in English:

sine qua non

noun

  • An essential condition; a thing that is absolutely necessary:

    ‘grammar and usage are the sine qua non of language teaching and learning’
    • ‘The study subjects obviously are the sine qua nons of a clinical trial.’
    • ‘Adopt these strategies for putting the sine qua non of job search success - networking - to the test.’
    • ‘There are three sine qua nons of guerilla warfare.’
    • ‘Clearly the first of two sine qua nons is to be able to express one calculated column in terms of another.’
    • ‘This practice, one of the sine qua nons of Hungarian rural life, has lost much of its original sacral, ritual meaning.’

Origin

Latin, literally (cause) without which not.

Pronunciation

sine qua non

/ˌsɪni kwɑː ˈnəʊn//ˌsʌɪni kweɪ ˈnɒn/