Christ, Irish is a **** language. Let's see
Dearc is pronounced like shark, or it could be referring to our word for red, which is dearg, which rhymes with garage (English pron not American) or jarret, that kind of thing. The second bit? Wow. Hmm.
sgiathanach: well the last part is "ock" the bit spelled athan is as it sounds - "ah-han", but the first part - I think "ski or she", so the whole thing would be like she-ah-han-ock. Maybe. Shoulda just called it big ****ing flying reptile thing.
So: shark she-ah-han-ock. Right. Much easier.
Fetcher might be able to weigh in on this too. Scottish is very like Irish but not identical, so I may have got pronunciation a little wrong.