The name Jebusite in the Bible
The people called Jebusites are possibly the descendants of one unmentioned Jebus, who in turn is then a descendant of Canaan, son of Ham, son of Noah (Genesis 10:16). However, the name Jebus is only applied to Jerusalem (Judges 19:10, 1 Chronicles 11:4), and the Jebusites may just be the townsfolk of Jebus, all somehow descending from Canaan, but not necessarily through a younger single ancestor.
The Jebusites were probably the first settlers of the area that would later be Jerusalem. King David's capital was originally Hebron, but he moved it to Jerusalem after conquering the latter from the Jebusites (2 Samuel 5:6-10). It should be noted that prior to David's annexation of Jerusalem, Israel once before conquered, burned and apparently abandoned Jerusalem (Judges 1:8).
A famous Jebusite is Araunah, who tries to give a piece of land to king David for him to build an altar to stop the plague (2 Samuel 24:16-25). David won't have anything of it and ends up buying the land from Araunah.
Etymology of the name Jebusite
The name Jebusite comes from the Hebrew verb בוס (bus) meaning to trample down:
None of the sources used offer an interpretation of the ethnonym Jebusite, but for a meaning of the name Jebus, Jones' Dictionary of Old Testament Proper Names reads Treading Down and NOBSE Study Bible Name List has Trodden Underfoot.