Hide in a corner of Greek island (7)
I believe the answer is:
secrete
'hide' is the definition.
(I know that secrete is a kind of hide)
'corner of greek island' is the wordplay.
'corner of' becomes 'SE' (the south eastern corner of something).
'greek island' becomes 'crete' (Crete is a Greek island).
'se'+'crete'='SECRETE'
'in a' acts as a link.
(Other definitions for secrete that I've seen before include "Cache" , "Hold and send out substance into the body as gland does" , "Release bodily fluid" , "Hide - discharge" , "Place out of sight, hide" .)