Pronunciation: ˌ si-ni- ˌ kwä- ' nän, - ' n ō n also ˌ s ē -; also ˌ s ī -ni- ˌ kw ā - ' nän
Function: noun
Inflected Form: plural sine qua nons also sine qui · bus non \ - ˌ kwi-( ˌ )bu ̇ s- also - ˌ kw ī - \
Etymology: Late Latin, without which not
Date: 1602
: something absolutely indispensable or essential <reliability is a sine qua non for success>