They're big in Hollywood (4)
I believe the answer is:
egos
'they're big in hollywood' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for egos that I've seen before include "Lots of self-esteem" , "feelings of self-importance" , "Self-images" , "People's personal pride - the parts of them that are conscious" .)