What does Genesis 10:16 mean?

This verse continues a list of the sons of Canaan, Noah's great-grandsons through his son, Ham. These sons of Canaan will become the Canaanites, the peoples occupying the Promised Land, which the people of Israel will come to conquer after the Exodus from Egypt (Exodus 3:17). Unfortunately, while other nations had their flaws, the Canaanite peoples would become especially wicked. This, more than anything else, is what motivates God to send Israel as a form of judgment (Deuteronomy 9:3–6). This flows from the curse given to Canaan by Noah, on account of Ham's dishonoring of his father (Genesis 9:20–25).

Verse 16 mentions the Jebusites, the Amorites, and the Girgashites. The Jebusites settled in what would later become the city of Jerusalem (Judges 1:21; 1 Chronicles 11:4).