Gangster grabs lowly vagrant in star-studded area (9)
I believe the answer is:
hollywood
'star-studded area' is the definition.
(area where lots of celebrities live)
'gangster grabs lowly vagrant' is the wordplay.
'gangster' becomes 'hood' (I've seen this in another clue).
'grabs' means one lot of letters goes inside another.
'vagrant' is an anagram indicator (vagrant can mean wandering around).
'lowly' anagrammed gives 'llywo'.
'hood' going around 'llywo' is 'HOLLYWOOD'.
'in' is the link.
(Other definitions for hollywood that I've seen before include "Where Frankie goes" , "in LA?" , "Cinematically brash and romantic" , "There's a place for tinsel" , "California suburb" .)