a group of families or households, as among the Scottish Highlanders, the heads of which claim descent from a common ancestor: the Mackenzie clan.
2.
a group of people of common descent; family: Our whole clan got together for Thanksgiving.
3.
a group of people, as a clique, set, society, or party, especially as united by some common trait, characteristic, or interest: a clan of actors and directors.
4.
Anthropology.
a.
the principal social unit of tribal organization, in which descent is reckoned exclusively in either the paternal or the maternal line.
b.
a group of people regarded as being descended from a common ancestor.
Origin: 1375–1425; late Middle English (Scots ) < Scots Gaelic clann < Old Irish cland offspring < Latin planta scion, plant, perhaps directly < British Celtic; compare Welsh plant children
c.1425, from Gael. clann "family, stock, offspring," akin to O.Ir. cland "offspring, tribe," both from L. planta "offshoot" (see plant (n.)). Gaelic (Goidelic) Celtic had no initial p-, so it substituted k- or c- for L. p-.