The Manassehites: from Machir, the family of the Machirites (now Machir became the father of Gilead); from Gilead, the family of the Gileadites.

The descendants of Machir son of Manasseh went to Gilead, took it, and dispossessed the Amorites who were in it.

So Moses gave Gilead to Machir, son of Manasseh, and he lived there. ¹ 

¹ Then the daughters of Zelophehad son of Hepher, the son of Gilead, the son of Machir, the son of Manasseh of the families of Manasseh, ²  the son Joseph came forward. Now these are the names of his daughters: Mahlah, Noah, Hoglah, Milcah, and Tirzah.

Then the heads of the family groups ¹  of the Gileadites, the descendant of Machir, the descendant of Manasseh, who were from the Josephite families, approached and spoke before Moses ²  and the leaders who were the heads of the Israelite families. ³