Gahan (surname) Irish language "Mac Gaoithín", meaning "son of "Gaoithín"", although the more common Anglicised form of this Gaelic name is "McGeehan" in Ulster. Gahan (surname) Gahan (and its variant Gahame) is a surname with several different origins. One origin of the surname is from a reduced form of "McGahan", which is in turn an Anglicised form of the Irish language "Mac Eacháin", meaning "son of "Eachán"". Another origin of the name, in Leinster, is from a reduced form of the Irish language "Ó Gaoithin", meaning "descendant of "Gaoithín"". The personal name "Gaoithín" is a diminutive of "gaoth", meaning "wise", or "wind".
Mac and Mc together A 2007 book in its tenth edition states that "most library catalogs" sort Mac and Mc names as if spelled M-a-c. Among the guides which generally recommend separating Mac and Mc so that names will be sorted as they are spelled are ISO 999, The Chicago Manual of Style, "Butcher's Copy-editing: The Cambridge Handbook for Editors, Copy-editors and Proofreaders", "The New York Times Manual of Style and Usage", and "The SBL Handbook of Style". Mac and Mc together A convention of sorting names with the Scottish and Irish patronymic prefixes Mac and Mc together persists in library science and archival