Gaelic: Cleireach
Various origins of Clerk as a name exist.  Examples are bookkeeeper, scribe, man of business and priest.
One of the 17 tribes of Clan Chattan was Clan Clerich.  Some of the names that can be included are, CLARK, CLARKE, CLARKSON, CLEARY, CLERK, LEARY, MacCHLERICH, MacCHLERY, MacCLAIR, MacCLEAR, MacCLEARY, MacCLERIE, MacLEAR, MacLERIE.

The tartan was one in the 1819 Key Pattern Books of Wilson of Bannockburn.