WordNet (r) 3.0 (2006):

Judah
    n 1: (Old Testament) the fourth son of Jacob who was forebear of
         one of the tribes of Israel; one of his descendants was to
         be the Messiah
    2: an ancient kingdom of southern Palestine with Jerusalem as
       its center [syn: Judah, Juda]

Easton's 1897 Bible Dictionary:

Judah
   praise, the fourth son of Jacob by Leah. The name originated in
   Leah's words of praise to the Lord on account of his birth: "Now
   will I praise [Heb. odeh] Jehovah, and she called his name
   Yehudah" (Gen. 29:35).

     It was Judah that interposed in behalf of Joseph, so that his
   life was spared (Gen. 37:26, 27). He took a lead in the affairs
   of the family, and "prevailed above his brethren" (Gen. 43:3-10;
   44:14, 16-34; 46:28; 1 Chr. 5:2).

     Soon after the sale of Joseph to the Ishmaelites, Judah went
   to reside at Adullam, where he married a woman of Canaan. (See
   ONAN; TAMAR.) After the death of his wife
   Shuah, he returned to his father's house, and there exercised
   much influence over the patriarch, taking a principal part in
   the events which led to the whole family at length going down
   into Egypt. We hear nothing more of him till he received his
   father's blessing (Gen. 49:8-12).


Hitchcock's Bible Names Dictionary (late 1800's):

Judah, the praise of the Lord; confession