A Maacathite was a person from the land of Maacah. This land was near Geshur and close to the border of the land given to the half-tribe of Manasseh (Deuteronomy 3:14; Joshua 12:5; 13:11). Jair took control of this land, but he and his people could not remove the Maacathites and Geshurites who still lived there (Joshua 13:13).
One Maacathite named Eliphelet joined David’s army. He was one of David’s "mighty men" (2 Samuel 23:34). In another list, he is called a Mekerathite (1 Chronicles 11:36). This may be a different name for the same place or person.
The Maacathites were not friendly toward Israel. Many years later, after Babylon destroyed Jerusalem, a man named Jaazaniah (whose father was a Maacathite) joined Ishmael the Ammonite to fight against Gedaliah. Gedaliah had been chosen by King Nebuchadnezzar to govern the city (2 Kings 25:23; Jeremiah 40:8).