Owing to the long history, the inconsistency in anglicizing Gaelic names, and the changes in the English language over the centuries, many surnames of today can trace their ancestry back to the Morrisons. These are known as “septs” of the clan. Not all families with these “sept” names are necessarily Morrisons, however, as many chose (or were given) names that sounded like pre-existing English names.
The primary septs most often recognized as being Morrisons are Gilmore, Brieve and MacBrieve. Other families that could be Morrisons include Breive, Gillamor, Gillemoire, Gillemor, Gillemore, Gillemur, Gillemure, Gilmer, Gilmoir, Gilmor, Gilmour, Gilmoure, Gilmur, Gilmure, Gylmor, MacBreive, MacGilmor, MacIllimhier, Moris, Morison, Morris, Morrieson, Morrison, Murieson, Murison and Murrison.