Girl getting a passage back finally to Caicos Islands (9)
I believe the answer is:
galapagos
'islands' is the definition.
(I've seen this before)
'girl getting a passage back finally to caicos' is the wordplay.
'girl' becomes 'gal' ().
'getting' means one lot of letters go next to another.
'passage' becomes 'gap'.
'back' shows that the letters should be reversed in order.
'finally' indicates one should take the final letters.
The last letters of 'to caicos' are 'os'.
'gap' backwards is 'pag'.
'gal'+'a'+'pag'+'os'='GALAPAGOS'
(Other definitions for galapagos that I've seen before include "Pacific nature reserve islands" , "tortoises" , "tortoise" , "- Islands are home to Darwin's finches" , "somewhere in the Pacific" .)