Alexander O'Neal's beginning to wear mask? (4)
I believe the answer is:
pope
'alexander' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pope that I've seen before include "author" , "fisherman's successor" , "Vatican head" , "Pontiff" , "St Peter was the first" .)