Not everyone in the Mackenzie Clan had the name Mackenzie or Mckenzie. There were many surnames of the family and of allied or dependent families. These other names are commonly called "septs of the clan", but according to Electric Scotland preferred modern usage is to avoid the use of the term "sept" and to simply describe these as surnames or family names.
Here is a list of known names belonging to the clan.
"MacCainnigh" in old Gaelic, or "MhicCoineach" in modern Gaelic, the name Mackenzie is literally, "Son of Kenneth", Kenneth being "fair one" or "bright one", and it is only translation into English that has led to differences in the spelling of the name today.