Big Apple baseballer (6)
I believe the answer is:
yankee
'big apple baseballer' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for yankee that I've seen before include "American (loosely)" , "Zulu comes after this" , "Union soldier in the American Civil War" , "Native of Northern US" , "US northerner to a southerner" .)