Answer: abyssal
AnswerCrossword Clue
ABYSSALLike a chasm
ABYSSALExtremely deep
ABYSSAL... zone (deep-sea realm)
ABYSSALOf the deep-sea floor
ABYSSALSo deep as to be unmeasurable
abyssalvery deep
abyssalof or pertaining to the biogeographic zone of the ocean bottom between the bathyal and hadal zones: from depths of approximately 13,000 to 21,000 ft. (4000 to 6500 m)
abyssalof or like an abyss; immeasurable; unfathomable