'Secret' in the Bible

Benaiah, the son of Jehoiada, a fighting-man of Kabzeel, had done great acts; he put to death two young lions going into their secret place; and he went down into a hole and put a lion to death in time of snow.

But the chiefs of the children of Ammon said to Hanun, Does it seem to you that David is honouring your father, by sending comforters to you? is it not clear that these men have only come to go through the land and to make secret observation of it so that they may overcome it?

And Ornan, turning back, saw the angel, and his four sons who were with him went to a secret place. Now Ornan was crushing his grain.