Quote Originally Posted by Peelee View Post
Ok, so distilling the relevant part here, I'd say that being called both the Alpha Celestial and the Progenitor means it was the first. You said earlier there was no indication of it being older, but I'd imagine that being called "the progenitor" and "the alpha celestial" are indications that it's older. Or whatever word Marvel wants to use if they want to play weird time games. Doesn't matter. Simplifying to the point a child could understand, thats probably just the first celestial.
Might be 'the first one we are aware of' or 'the first one that did something that interfered with events on Earth.' A cursory search doesn't indicate anything attaching further importance to the 'alpha' designation, so it may well just be a random word the writer threw in there to make it sound more important/mysterious than the current day crop of Celestials - the Progenitor doesn't really seem to be unusual among Celestials for anything other than the method of its death.