Cite
 

Meaning of causa sine qua non*

cau•sa si•ne qua non

Pronunciation: (kou'sä si'ne kwä nōn' Eng. kô'z&schwa sī'nē kwā non', kô'z&schwa sin'ā kwä nōn'), [key]
— Latin. Latin.
  1. an indispensable condition; requisite.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.