In Cathcart it is the second component that is the river name. An early spelling, Kerkert, shows that it means "fortress (caer) on the River Cart". The river name, Cart, is believed to mean "stony". All from Nicolaisen's "Scottish Place-Names". Whiskin, according to Paul Reaney, is Wise-kin, a diminutive of WISE; probably used as a given name rather than a description of the original bearer.