Island chap, brown, holding hat (9)
I believe the answer is:
manhattan
'island' is the definition.
(I've seen this before)
'chap brown holding hat' is the wordplay.
'chap' becomes 'man' (chap can mean a man).
'brown' becomes 'tan' (tan is a kind of brown).
'holding' means one lot of letters goes inside another.
'man'+'tan'='mantan'
'mantan' enclosing 'hat' is 'MANHATTAN'.
(Other definitions for manhattan that I've seen before include "Vermouth and whiskey, with a dash of bitters" , "One of the five boroughs of New York City" , "It blended with spirit" , "Island of New York - cocktail" , "Cocktail of whiskey and sweet vermouth" .)