I don't think so. The Celts are Nordics. And Germans and others in continental Europe north of the Alps are part Celtic. Some in some regions are heavily Celtic.

The Celts spoke various Celtic languages, which are divided into different branches: Continental Celtic and Insular Celtic. Examples of Insular Celtic languages include Irish, Scottish Gaelic, Welsh, and Breton. The specific Celtic language spoken would depend on the region and time period.

Celtic have a larger support.

Ellis D. Evans has written:

'Children and youth' -- subject(s): Developmental psychology, Social psychology

'Study guide for Boyd R. McCandless: 'Children, behavior and development'

The tenant of Celtic Park is Celtic F.C. in Scotland.