primeval

Universal Words (also primaeval) adjective [usuallybeforenoun] 1 from the earliest period of the history of the world, very ancient: primeval rocks / forests * primeval soup (= the mixture of gases and substances that is thought to have existed when the earth was formed and from which life started) 2 (formal) (of a feeling, or a desire) very strong and not based on reason, as if from the earliest period of human life: primeval instincts / urges