Thoughts on Galicia?

[Damion]

Damion,

I agree with what you are saying. And although the language was a defining element for many in the past, it seems less emphasized today. After all, most Scots or Irish people don't speak Gaelic as a mother tongue, but this does not change their identification with a Celtic cultural heritage. As a Scottish-American, I certainly don't speak Gaelic, either.

Most Scots and Irish don't speak Gaelic which is why those countries are not Celtic (though they are home to Celtic cultures), particularly Scotland which has strong competing Germanic cultural elements. The language is less emphasized now because of the large number who don't speak it but feel an attachment.
Romantic feelings don't overcome pragmatic realities. People can pretend to be something but without all the necessary cultural cues they're just pretending. The reality is that without a community of Celtic speakers there are no Celts as materially and even culturally there is little difference between people living in English speaking countries. Things like religion and lifestyle have bigger impacts on cultural expression than ancestral ties.

[LKM]

While the term that became Celtic came from a Roman description of the tribes of Brittan as like the Celtae tribes of France, the idea of a Celtic identity is far more recent. The Idea of Celtic Nations did not show up until the 18th century. Some of the people groups that were identified as Celtic by people in the 18th and 19th centuries have only recently adopted the concept of Celtic Identity.

The term Celtic keeps changing, and now normally reefers to a language family. The term has also been used for the peoples, or families, whose ancestors spoke Celtic languages. Most of what is now Europe once spoke Celtic languages, including in Galicia, Spain. As different people define the work Celtic differently it is up for interpretation.

The Celtiberi tribes of Spain once spoke a language much like the ancient Irish and had a culture that many people today see as Celtic. A study of the pre-Roman culture of Galicia, Spain could go on for several decades or centuries. From what I understand there were in ancient times several cultural similarities and trade connections between what is now Galicia, Ireland, Scotland, and Wales. DNA research has also shown a strong genetic connection between these peoples.

As for kilt-like garments, or tartan in traditional garments the discussion can go on for a long time. Kilt-like garments and tartan use spans most of the world, even back to ancient times.

https://en.wikipedia.org/wiki/Names_of_the_Celts
https://en.wikipedia.org/wiki/List_of_Celtic_tribes
https://en.wikipedia.org/wiki/Men%27s_skirts
https://en.wikipedia.org/wiki/Celtiberians

[Damion]

There is no especial genetic link between Galicia and the British Isles, I believe that is between the British Isles and the Basques. There is a general link between the Isles and the western coast of Europe as would be expected.
The term Celtic, other than in the last couple of decades has always had a language component attached to it. The Boston Celtics is sort of an exception. They are named for an earlier team from New York called the Celtics and were named at a time when Boston was filled with Irish. The obvious Irish team named Celtic was the original Celtic FC in Glasgow which was founded by Irish immigrants who in the late 19th century would have still been Celtic speakers.
Incidentally, Henry McCarty aka Billy the Kid, spoke Irish as he was born into an Irish community in New York where the language was still strong and where the Celtic name for later basketball teams came from.

[LKM]

I know I have seen a report on the genetic connection somewhere yet on a quick search I am only finding a connection with the Basques. I will see if I can find it again.

I agree that for the greater part of the last few hundred years the term Celtic has mainly been used for languages. The term, as with many, is interpreted different to different people or in different context.