'Secret' in the Bible

But the chiefs of the children of Ammon said to Hanun their lord, Does it seem to you that David is honouring your father by sending comforters to you? has he not sent his servants to go through the town and make secret observation of it, and overcome it?

But he will certainly have taken cover now in some hole or secret place; and if some of our people, at the first attack, are overcome, then any hearing of it will say, There is destruction among the people who are on Absalom's side.

And if I had falsely put him to death (and nothing may be kept secret from the king), you would have had nothing to do with me.

Then the men of Israel came to the king and said, Why have our countrymen of Judah taken you away in secret and come over Jordan with the king and all his family, because all his people are David's men?

They will be wasted away, they will come out of their secret places shaking with fear.