Answer: existential

AnswerCrossword Clue
EXISTENTIALLike "The Plague"
EXISTENTIALLike Sartre's philosophy
existential(of a proposition) Affirming or implying the existence of a thing
existentialConcerned with existence, esp. human existence as viewed in the theories of existentialism
existentialOf or relating to existence
existentialsomething that exists