Young creature associated with a Caribbean island (4)
I believe the answer is:
cuba
'caribbean island' is the definition.
(I've seen this before)
'young creature associated with a' is the wordplay.
'young creature' becomes 'cub' (eg bear cub).
'associated with' says to put letters next to each other.
'cub'+'a'='CUBA'
(Other definitions for cuba that I've seen before include "Largest West Indies island" , "Country famous for its cigars" , "Hemingway's stamping-ground" , "Island N. of Jamaica" , "Castro's republic" .)