How to pronounce “megastar” in English

Even in 1980, he was already a megastar with costumes.

To me, she's the first black female megastar.

And whereas Duke was a big star, a major star, Johnny turns out to be a megastar.

had a life in entertaining, gets on stage and totally mumbles the name, forgets what he's supposed to say, and says, and now I'm going to introduce the amazing megastar, Adele