Cuts in the middle of Greece produce blackout (7)
I believe the answer is:
eclipse
'blackout' is the definition.
(I've seen this before)
'cuts in the middle of greece' is the wordplay.
'cuts' becomes 'clips' (clipping is a kind of cutting).
'in' is an insertion indicator.
'the middle of' means to look at the middle letters.
The centre of 'greece' is 'ee'.
'clips' put within 'ee' is 'ECLIPSE'.
'produce' is the link.
(Other definitions for eclipse that I've seen before include "Black out" , "The blocking of light of one heavenly body by another" , "When light's dropped" , "Surpass in achievement" , "Obscure, as moon may the sun" .)