'Deadly' in the Bible

Their tongue is a deadly arrow that speaks deceit. With his mouth a person says, "Peace,' to his friend, but inwardly he sets a trap for him.

"They'll die of deadly diseases. People won't mourn for them, nor will they be buried. They'll be dung on the surface of the ground, and they'll come to an end with the sword and with famine. Their dead bodies will be food for the birds of the sky and the animals of the land."