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".
Poland (surname) the examples where the 'Mac' or 'Mc' has been dropped can be explained for several reasons. In English controlled areas of Ireland (especially around The Pale), it was declared that the Irish take on names in an English form and many were required to do so in order to do business with the powers that be, or to obtain a tenancy on English controlled land. Census takers were also allowed to use either form, with or without the Gaelic prefix. It also was not uncommon for the 'Mac' or 'Mc' prefix to simply be incorporated into the surname to result