Sailor from Costa Rica (3)
I believe the answer is:
tar
'sailor' is the definition.
(tar is a kind of sailor)
'from costa rica' is the wordplay.
'from' indicates the answer is hidden within the clue.
'TAR' is hidden within 'costa rica'.
(Other definitions for tar that I've seen before include "Sticky substance - seaman" , "Black substance, used on roads" , "Sailor - laid on road" , "Dark flammable liquid" , "Sticky black stuff" .)