This name is Gaelic is Ó Daimhín and the ancestor who gave the sept its name was Daimhín, died 966, the son of Cairbre Dam Argait, King of Oriel.  A brother of Daimhín called Cormac was ancestor of the Maguires and the O'Devines, Lords of Tirkennedy.  It was a leading Co. Fermanagh sept up until and including the fifteenth century.  Later, the power of the leading family was broken by pressure from the O'Neills in the north and the Maguires in the south.  However, the name is still known in Fermanagh, although more common in counties Tyrone and Derry.  The name stems from the word damh, meaning 'ox', and not from dámh, meaning 'poet'.  The sept gave Clogher in Co. Tyrone its original name, Clochar Mac nDaimhín.


Clan From the Gaelic clann which means literally 'children'.
Mac- From the Gaelic mac, meaning 'son'
O' From the Gaelic Ó, meaning 'grandson', 'grandchild' or 'descendant'; Ní is the femine form of Ó, meaning 'daughter' or 'descendant'
Plantation (Ulster) The redistribution of escheated lands after the defeat of the Ulster Gaelic lords and the 'Flight of the Earls' in 1607.  Only counties Donegal, Derry, Tyrone, Armagh, Fermanagh and Cavan were actually 'planted', portions of land there being distributed to English and Scottish families on their lands and for the building of bawns.
Sept A family group of shared ancestry living in the same locality
Undertakers Powerful English or Scottish landowners who undertook the plantation of British settlers on the lands they were granted.
Gaelic This word in Ireland has no relation to Scotland.  As a noun it is used to denote the Irish language, as an adjective to denote native Irish as opposed to Norman or English origin.
Erenagh From the Irish Gaelic airchinneach, meaning 'hereditary steward of church lands'.  A family would hold the ecclesiastical office and the right to the church or monastery lands, the incumbent at any one time being the erenagh.