'Adversary' in the Bible

And her adversary also provoked her sore, for to make her fret, because the LORD had shut up her womb.

and thou hast beheld an adversary in My habitation, in all that He doth good with Israel, and there is not an old man in thy house all the days.

Samuel said, “Why then do you ask me, since the Lord has departed from you and has become your adversary?

And the princes of the Philistines were wroth with him; and the princes of the Philistines said unto him, Make this fellow return, that he may go again to his place which thou hast appointed him, and let him not go down with us to battle, lest in the battle he be an adversary to us: for wherewith should he reconcile himself unto his master? should it not be with the heads of these men?