Sa·tan 
(sātn)
(sātn)n.
In Abrahamic religions, a powerful spiritual being, the tempter and persecutor of humanity, sometimes considered as an angel who rebelled against God and became the Devil.
[Middle English, from Old English, from Late Latin Satān, from Greek Satanas, Satān, from Hebrew śāṭān, devil, adversary, from śāṭan, to accuse, act as adversary; see śṭn in the Appendix of Semitic roots.]