Boyd’s Bible Dictionary:
(troop). (1) Jacob’s seventh son (Gen. 30:11-13; 49:19; Num. 1:24-25). Tribe settled east of Jordan, and became a fierce, warlike people. Carried captive by Tiglath-pileser (1 Chron. 5:26). (2) A prophet and David’s seer (1 Sam. 22:5; 1 Chron. 21:9-19; 29:29; 2 Chron. 29:25).
Concise Bible Dictionary:
He was with David when he fled from Saul, and gave him counsel (1 Sam. 22:5). Whether he continued with David during his rejection is not recorded. He was with him at the close of his reign, and to him was given the painful duty of announcing God’s judgments upon David for numbering the people. He is called David’s “seer,” which would seem to imply that he had been with him all along (2 Sam. 24:11-19; 1 Chron. 21:9-19; 2 Chron. 29:25). The acts of David were written in “THE BOOK OF GAD the seer,” of which there is no further record, and which has not been handed down (1 Chron. 29:29).
Strong’s Dictionary of Greek Words:
Meaning:
of Hebrew origin (1410); Gad, a tribe of Israelites
Potts’ Bible Proper Names:
Troop armed; company prepared:―an Israelitish tribe, Rev. 7:5. {Turma armata}