Capri: so awfully dull (7)
I believe the answer is:
prosaic
'dull' is the definition.
(similar in meaning)
'capri so awfully' is the wordplay.
'awfully' indicates an anagram.
'capri'+'so'='capriso'
'capriso' anagrammed gives 'PROSAIC'.
(Other definitions for prosaic that I've seen before include "boring!" , "flat" , "Pedestrian, unimaginative" , "Ordinary - not poetical" , "Banal" .)