Brown Driver Briggs

 Hor = "mountain"
1. the mountain on which Aaron died; situated on the eastern side of
the valley of Arabah, the highest of the whole range of sandstone
mountains in Edom; on the eastern side is the ancient city of Petra
2. the mountain named as one of the marks of the northern boundary of
the land which the children of Israel were about to conquer; located
in Lebanon