Sine qua non

Sine qua non (/ˌsaɪni kweɪ ˈnɒn/; Latin: [ˈsine kwaː ˈnoːn]) or condicio sine qua non (plural: condiciones sine quibus non) is an indispensable and essential action, condition, or ingredient. It was originally a Latin legal term for "[a condition] without which it could not be", or "but for..." or "without which [there is] nothing".