Adjectives

(a)existentialof or as conceived by existentialism“an existential moment of choice”
(a)existentialrelating to or dealing with existence (especially with human existence)
(s)experiential, existentialderived 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)