This surname is numerous in counties Armagh and Antrim.  It is said to have originated in the case of early emigrants from Ireland who thus acquired the Norman name of de Yrlande, some of their descendants returning eventually to this country.  In its modern form it occurs in the 1664 Hearth Money Rolls for Co. Armagh, and Samuel Ireland was one of the Poll-tax Commissioners for Co. Louth in 1660.

In mediavel records we meet more frequently the cognate name le Ireis; its modern form, Irish was formerly well known in Co. Kilkenny; eight families of the name are in Griffith's Valuation of that county in 1851, in which three Irelands also appear.  Ireland is now rare there but fairly numerous in Ulster.Mac)



Clan From the Gaelic clann which means literally 'children'.
Mac- From the Gaelic mac, meaning 'son'
O' From the Gaelic , meaning 'grandson', 'grandchild' or 'descendant'; N is the femine form of , 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.