Any of the Fab Four (6)
I believe the answer is:
beatle
'any of the fab four' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for beatle that I've seen before include "John, Paul or George, say" , "eg Ringo" , "One of the famous four pop musicians, says Paul or John" , "Paul, Ringo, John or George" .)