About the McWilliam surname
The surname McWilliam is associated with a patronymic formation. The Mac-/Mc- formation is traditionally patronymic and means “son of” in Gaelic languages. The surname may originally have expressed descent before becoming fixed as a hereditary family name. The prefix in McWilliam belongs to a family of Gaelic forms traditionally used in patronymic surnames and is generally associated with descent.
Pronunciation:
Èm-séoui-lirm/ɛmsewɪliʁm/