'Deep' in the Bible

I say to the rest of you in Thyatira, who do not hold this teaching, who haven’t known the deep things of Satan—as they say—I do not put any other burden on you.

And at the sounding of the fifth angel I saw a star falling from heaven to the earth: and there was given to him the key of the great deep.

And he made the great deep open and a smoke went up from it, like the smoke of a great oven; and the sun and the air were made dark because of the smoke.

They have over them as king the angel of the great deep: his name in Hebrew is Abaddon, and in the Greek language Apollyon.

And when they have come to the end of their witness, the beast which comes up out of the great deep will make war on them and overcome them and put them to death.

The beast which you saw was, and is not; and is about to come up out of the great deep, and to go into destruction. And those who are on the earth, whose names have not been put in the book of life from the first, will be full of wonder when they see the beast, that he was, and is not, and still will be.

And I saw an angel coming down out of heaven, having the key of the great deep and a great chain in his hand.

And put him into the great deep, and it was shut and locked over him, so that he might put the nations in error no longer, till the thousand years were ended: after this he will be let loose for a little time.