What is the “correct” pronunciation of the word Celtic?
Boston Celtic fans prefer the soft c sound, but Irish dancers tend to go with the hard c sound.
I prefer the /k/ sound. I like the way the word feels as I say /kel tik/. A less frivolous reason is that I learned to pronounce the word with the hard c when I studied Celtic literature.. In the Irish epic The Táin Bó Cuailnge, for example, the letter c is pronounced /g/ or /k/. Academic usage tends to prefer the hard c pronunciation.
On the other hand, one of my often-consulted authorities, H. W. Fowler, has this to say:
The spelling C-, and the pronunciation /s/, are the established ones, and no useful purpose seems to be served by the substitution of k-.
Fowler was, of course, an old school Englishman whose Modern English Usage was first published in 1926. It’s doubtful that he had much sensitivity when it came to Celtic pride.
I’d say that Celtic is one of those words whose pronunciation changes according to context. Go with your preference in general. Find out how company employees, team members, performers, or club members pronounce it when it occurs in a title.