Specific study introducing Greek island (8)
I believe the answer is:
concrete
'specific' is the definition.
(thesaurus)
'study introducing greek island' is the wordplay.
'study' becomes 'con' (I've seen this before).
'introducing' is a charade indicator (letters next to each other).
'greek island' becomes 'crete' (I've seen this before).
'con'+'crete'='CONCRETE'
(Other definitions for concrete that I've seen before include "factual type of evidence?" , "Definite; building material" , "Actual - stuff made with cement" , "Real, not abstract" , "Strong, hard, building material" .)