Spot on a map (4)
I believe the answer is:
isle
'spot on a map' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for isle that I've seen before include "Fair one is in shipping bulletin" , "Christmas or Easter, perhaps" , "Wight, Man or Skye" , "Body of land surrounded by water" , "See 11 Across" .)