sine qua non

noun

si·​ne qua non ˌsi-ni-ˌkwä-ˈnän  -ˈnōn 

 also  ˌsē-;

 also  ˌsī-ni-ˌkwā-ˈnän

plural sine qua nons also sine quibus non -ˌkwi-(ˌ)bu̇s- 

 also  -ˌkwī-

: something absolutely indispensable or essential

reliability is a sine qua non for success

Did you know?

Sine qua non can be translated literally as "Without which, not." Though this may sound like gibberish, it means more or less "Without (something), (something else) won't be possible." Sine qua non sounds slightly literary, and it shouldn't be used just anywhere. But it actually shows up in many contexts, including business ("A solid customer base is the sine qua non to success"), show business ("A good agent is a sine qua non for an actor's career"), and politics ("His support was really the sine qua non for her candidacy").

Synonyms

• must
• requirement
• necessity

Examples of sine qua non in a Sentence

Patience is a sine qua non for this job.

an extensive grounding in mathematics is a sine qua non for a career in architecture

Recent Examples on the Web

While not denying the parallels between Muggle and magical technologies, Oakes’s conclusions depend on ignoring magical people’s complete dependence on a wand—the indisputable sine qua non of reliable spellwork. —Literary Hub, 26 June 2025

Possessing ethical values is a sine qua non for any political leader, regardless of political affiliation. —Tom Jurkowsky, Baltimore Sun, 5 June 2025

At that point, sunglasses lose their sine qua non purpose to protect our eyes, becoming a purely ornamental element capable of elevating an entire outfit. —Teresa Romero Martínez, Glamour, 22 Mar. 2025

The sine qua non for an economic deal is that Ukrainian leadership wants a peace deal. —CBS News, 2 Mar. 2025

Word History

Etymology

Late Latin, without which not

First Known Use

1602, in the meaning defined above

Rhymes for sine qua non

• agamemnon
• automaton
• diencephalon
• panopticon
• phenomenon
• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon