Delia is somehow perfect (5)
I believe the answer is:
ideal
'perfect' is the definition.
(similar in meaning)
'delia is somehow' is the wordplay.
'is somehow' indicates an anagram.
'delia' anagrammed gives 'IDEAL'.
(Other definitions for ideal that I've seen before include "Just the ticket" , "Ailed (anag)" , "highly desirable" , "Conceptual" , "Textbook" .)