Kin Groups and Descent. In Gaelic culture, dann has a different meaning than the Scottish clan and the common anthropological term. The Irish clann traces descent through both males and females; thus, a clann is the entirety of all Persons descended from the clann progenitor (regardless of whom those persons may have married). This means that an individual will belong to several clanns simultaneously: his or her father's one or more clanns, plus his or her mother's. The clann is not necessarily exogamous. There are other categories of kin that overlap with the clann. A person has a body of known relatives recognized as his or her kindred ("my People," mo mhuintir). A smaller kinship group is made up of those people considered relatives "by blood" ( gaolta ). Membership in these groupings corresponds to a very different System of naming than the Christian-name-plus-surname pattern of Anglo-Saxon lands. A person's descent is actually named, going back to one, two, or three patrilineal ancestors. There are also surnames, but the well-known O' of so many Irish names occurs less often in Gaelic: O' means "son of." Women instead carry the term Ní, "daughter of." Neither of these terms is used in a surname except on very formal occasions.
Kinship Terminology. The Gaelic kinship system uses bifurcate-collateral terminology, which is very different from the English system so widespread in Ireland.