'Deadly' in the Bible

They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover.

But the tongue can no man tame; it is an unruly evil, full of deadly poison.

And I saw one of his heads as it were wounded to death; and his deadly wound was healed: and all the world wondered after the beast.

And he exerciseth all the power of the first beast before him, and causeth the earth and them which dwell therein to worship the first beast, whose deadly wound was healed.