The name Celt originated with the ancient Greeks, who called the barbarian peoples of central Europe Keltoi. The Celts were a broad cultural-linguistic group. The Celts were never an empire ruled by one government.
Celtic society there was not a rigid class system imposed by birth.
Clann is a Gaelic word that means children. A clan is a family, descended from some notable individual, often bearing his name. The currant clan chief, who is the prime descendant of the founder, is nominally the father of the whole clan, having moral authority over all its members.
The general impression from all sources of evidence designates the Celtic aristocratic society as being tall, physically powerful men and women with fair or reddish hair, grey-blue eyes, light skins, oval faces, and fresh complexions.
The Celts were a very clean people, using soap long before the Romans did. The Celtic men and women of Britain sometimes wore swirling blue tattoos or paintings on their bodies.