Brown Driver Briggs

 Gad = "troop"
1. seventh son of Jacob by Zilpah, Leah's handmaid, and full brother
of Asher.
2. the tribe descended from Gad
3. a prophet during the time of David; appears to have joined David
when in the hold; reappears in connection with the punishment for
taking a census; also assisted in the arrangements for the musical
service of the "house of God"