How should the word Celtic be pronounced: as 'Seltic' or as 'Keltic'?

I've always said it with the hard C. "Keltic." Saying it like "Seltic" just sounds wrong to me.

The 's'eltics are a basketball team. But 'k'eltic and 'k'elt is how it's pronounced when talking about the ancient peoples & cultures of the British Isles. And yes, it's "The book of 'K'ells".

"Keltic." Hard C. However, if you are referring to the historic people known as the Celts, then you use the soft c, "selts." Clear as mud, right?

With a kicking K. Unless you're talking about the Glasgow football team... they're pronounced "Seltic". {The word is fundamentally from the Ancient Greek word "Keltoi". It's definitely a kicking K.}

However the Irish want it. The Boston (Keltics?)

Keltic, Keltic, Keltic. Every time I hear about the "S"eltics playing a game, I cringe at the sportscasters pronunciation. When Barack Obama recently told everyone his name was of ancient "S"eltic ancestry, it was almost as bad as George Bush's Nukular.

In Ireland, the pronunciation is with the K. Here in the U.S. they use the S sound.