'Secret' in the Bible

Then Pharaoh also called for the wise men and the sorcerers, and they also, the magicians of Egypt, did the same with their secret arts.

But the magicians of Egypt did the same with their secret arts; and Pharaoh’s heart was hardened, and he did not listen to them, as the Lord had said.

The magicians did the same with their secret arts, making frogs come up on the land of Egypt.

The magicians tried with their secret arts to bring forth gnats, but they could not; so there were gnats on man and beast.