Genesis 3:1 as erum, meaning "cunning", referring to the serpent or Satan (See note below).
Note: The consensus of the Biblical commentators in classical Judaism is that the "serpent" of the narrative in the Book of Genesis, was literally a serpent. They differ regarding what force it represented: The "evil inclination", "Satan", or the "Angel of Death". According to the Midrash, before this cunning beast was cursed, it stood erect and was endowed with some faculty of communication.