existential

The adjective is a learned borrowing from Late Latin existentiālis, exsistentiālis (“coming into or relating to existence”) + English -al (suffix meaning ‘of or pertaining to’ forming adjectives; and forming nouns of verbal action). Existentiālis, exsistentiālis are derived from Late Latin existentia, exsistentia (“existence”) + Latin -ālis (suffix forming adjectives of relationship); and existentia, exsistentia from Latin existēns, exsistēns (“being, existing; appearing, emerging; becoming”) (the present active participle of existō, exsistō (“to be, exist; to appear, emerge; to become”), from ex- (prefix meaning ‘away; out’) + sistō (“to cause to stand; to place, set; to halt, stop”) (ultimately from Proto-Indo-European *steh₂- (“to stand (up)”))) + -ia (suffix forming feminine abstract nouns).

The noun is derived from the adjective.