 The most common class of Gaelic surnames are those beginning with (Gaelic for "son"), such as  /  (MacLean).The female form is (Gaelic for "daughter"), so Catherine MacPhee is properly called in Gaelic,  (strictly, is a contraction of the Gaelic phrase , meaning "daughter of the son", thus really means "daughter of MacDonald" rather than "daughter of Donald").The "of" part actually comes from the genitive form of the patronymic that follows the prefix; in the case of , ("of Donald") is the genitive form of ("Donald").