Ahithophel
   brother of insipidity or impiety, a man greatly renowned for his
   sagacity among the Jews. At the time of Absalom's revolt he
   deserted David (Ps. 41:9; 55:12-14) and espoused the cause of
   Absalom (2 Sam. 15:12). David sent his old friend Hushai back to
   Absalom, in order that he might counteract the counsel of
   Ahithophel (2 Sam. 15:31-37). This end was so far gained that
   Ahithophel saw he had no longer any influence, and accordingly
   he at once left the camp of Absalom and returned to Giloh, his
   native place, where, after arranging his wordly affairs, he
   hanged himself, and was buried in the sepulchre of his fathers
   (2 Sam. 17:1-23). He was the type of Judas (Ps. 41:9).
   

Ahithophel, brother of ruin or folly