An opening, break or split.
And the LORD said, Behold, there is a place by me, and thou shalt stand upon a rock: and it shall come to pass, while my glory passeth by, that I will put thee in a CLIFT of the rock, and will cover thee with my hand while I pass by. ( Exodus 33:21-22 )
Bibliography Information"Entry for 'Clift'". A King James Dictionary.