'Secretly' in the Bible

Then Joshua, the son of Nun, sent two men from Shittim secretly, with the purpose of searching out the land, and Jericho. So they went and came to the house of a loose woman of the town, named Rahab, where they took their rest for the night.

So Joshua sent men quickly, and looking in his tent, they saw where the robe had been put away secretly with the silver under it.

And he gave them their orders, saying, Go and take up your position secretly at the back of the town: do not go very far away, and let all of you be ready:

But these five kings went in flight secretly to a hole in the rock at Makkedah.