Definition of "existential"

Jaspers' main concern has been with existential dread, which he regards not as a symptom of mental illness, but as a result of rejecting religious faith. He proposes that man's only way out of existential dread is through a “leap into faith” which reconciles man with himself and with God, and provides an experience of the absolute which transcends mere sense experience.

2013, J. E. Sieber, H. F. O'Neil, Jr., S. Tobias, Anxiety, Learning, and Instruction‎, Routledge

Here, therefore, we seek to assemble and assess the evidence to provide an overview of how serious trade is as an existential threat to avian taxa in Sundaic Indonesia.

2015, James Eaton et al., “Trade-driven extinctions and near-extinctions of avian taxa in Sundaic Indonesia”, in Forktail, page 2, column 2

To Musk, his vast fortune is a mere side effect of his ability not just to see but to do things others cannot, in arenas where the stakes are existential.

2021 December 13, Molly Ball, Jeffrey Kluger, Alejandro de la Garza, “Elon Musk: Person of the Year 2021”, in Time‎

In recent books on logic, distinction is made between two orders of inquiry concerning anything. First, what is the nature of it? how did it come about? what is its constitution, origin, and history? And second, What is its importance, meaning, or significance, now that it is once here? The answer to the one question is given in an existential judgment or proposition. The answer to the other is a proposition of value, what the Germans call a Werthurtheil […]

1902, William James, “Lecture I”, in The Varieties of Religious Experience […] ‎, London: Longmans, Green & Co., page 4

Some existential thinkers are concerned with artistic expression only indirectly, that is, they are passionately interested critics and analysts of art works.

1997, Thomas Hanna, “Albert Camus: Man in Revolt”, in William Leon McBride, editor, Sartre's French Contemporaries and Enduring Influences (Sarte and Existentialism), Garland, page 356

We argue that existentials form a radial category, with a prototype and less canonical instances, where the prototype is clearly definable but the actual borderline between existentials and other clause types is fuzzy.

2014, Silvia Luraghi, Tuomas Huumo, Partitive Cases and Related Categories, Walter de Gruyter GmbH & Co KG, page 153