'Existential' definitions:

Definition of 'existential'

From: WordNet
adjective
Derived from experience or the experience of existence; "the rich experiential content of the teachings of the older philosophers"- Benjamin Farrington; "formal logicians are not concerned with existential matters"- John Dewey [syn: experiential, existential]
adjective
Of or as conceived by existentialism; "an existential moment of choice"
adjective
Relating to or dealing with existence (especially with human existence)

Definition of 'Existential'

From: GCIDE
  • Existential \Ex`is*ten"tial\, a.
  • 1. Having existence. [Archaic] --Bp. Barlow. [1913 Webster]
  • 2. of or pertaining to, or having the character of, existentialism. [PJC]
  • 3. (Logic) specifying actual existence, rather than only possibility; as, the existential operator. [PJC] --{Ex`is*ten"tial*ly}, adv. [Archaic] [1913 Webster]
  • Existentially as well as essentially intelligent. --Colerige. [1913 Webster]