Surnames
The majority of Gaelic surnames are patronymic in nature and of Goidelic extraction, although epithets, geography or occupation and borrowings also occur in some surnames.
Caimbeul "crooked mouth" and Camshron "crooked nose" are two examples of surnames based on epithets, Friseal is an example of a borrowing (from Anglo-French Fresel).
The usage of patronymic surnames was much more varied than is generally assumed. Historically, clan surnames were used by the descendants or dependants of an ancestor but not generally by everyone in the clan territory. Only with the advent of a non-Gaelic speaking administration were clan surnames applied en-masse to people in a clan's territory.
Read more about this topic: Scottish Gaelic Personal Naming System