The terms "Harar" and "Hararite" are used to describe several of King David's "mighty men" in the Bible. A Hararite was someone who came from a place called Harar.
Shammah was one of the mightiest men of David. He was father of Jonathan. This is a different Jonathan than the son of King Saul who was a friend of David. Shammah was a Hararite (2 Samuel 23:11, 33; 1 Chronicles 11:34 has “Shagee”). Agee, the father of Shammah was also a Hararite (2 Samuel 23:11). Sharar, the father of Ahiam, is also called a Hararite (2 Samuel 23:33; in 1 Chronicles 11:35 he is called “Sachar”).
We are not completely sure what these terms mean. They might refer to a mountain village called Harar, or they might mean "mountaineer" (someone who lives in the mountains).