Zech. 3:1--"And he showed me Joshua the high priest standing before
the angel of the Lord, and Satan standing at his right hand to resist
him." (See vv. 1-5.) 1 Pet. 5:8--"Your adversary the devil." Luke
10:18. See for use of the word: Num. 22:22. By adversary is meant
one who takes a stand against another. Satan is the adversary of
both God and man.