Nickname for New York (3,3,5)
I believe the answer is:
the big apple
'nickname for new york' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for the big apple that I've seen before include "New York City" , "that could keep many doctors away?" , "first huge temptation?" , "Metropolis" , "Nickname for New York" .)