From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

Gizrites, or Gerizzites. A Bedouin tribe once dwelling in central Palestine, from whom mount Gerizim took its name, as another mount was named from the Amalekites when dwelling in ancient times in Ephraim ( Judges 12:15). Afterward driven to the southern border of Palestine, where with the Geshurites and Amalekites they were found by David in Saul's days ( 1 Samuel 27:8), rich in "sheep, oxen, asses, camels, and apparel." Read "Gerizzites."

International Standard Bible Encyclopedia [2]

gûr´zı̄ts (  1 Samuel 27:8 King James Version margin). See Girzites .