From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Gazites . The inhabitants of Gaza (wh. see),   Joshua 13:3 ,   Judges 16:2 .

Morrish Bible Dictionary [2]

See Gazathites

International Standard Bible Encyclopedia [3]

gāz´ı̄ts  : Inhabitants of Gaza, who were Philistines when the Israelites came into contact with them (  Joshua 13:3;  Judges 16:2 ), but there was an older stratum of population which occupied the place before the invasion of the Philistines, probably of Amorite stock.