Prosaic or functional heart of the island (5)
I believe the answer is:
corfu
'the island' is the definition.
(Greek island)
'prosaic or functional heart' is the wordplay.
'CORFU' is hidden within the letters.
But, I am not sure how this is indicated.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for corfu that I've seen before include "part of Greece" , "Greece's 'Kerkyra'" , "Largest of the Ionian Islands" , "Popular holiday island off West Greece" , "Island off west of Greece, popular for holidays" .)