'Signs' in the Bible

Then Caleb made signs to the people to keep quiet, and said to Moses, Let us go up straight away and take this land; for we are well able to overcome it.

And Joshua, the son of Nun, and Caleb, the son of Jephunneh, two of those who had been to see the land, giving signs of grief,

And the LORD said unto Moses, How long will this people provoke me? and how long will it be ere they believe me, for all the signs which I have shewed among them?

none of the men who have seen My glory and the signs I performed in Egypt and in the wilderness, and have tested Me these 10 times and did not obey Me,

When Balaam saw that it pleased the Lord to bless Israel, he did not go as he had done each time before [superstitiously] to seek omens and signs [in the natural world], but he set his face toward the wilderness (desert).