Raven's call is new, always about Rome (9)
I believe the answer is:
nevermore
'raven's call is' is the definition.
I can't tell whether this definition defines the answer.
'new always about rome' is the wordplay.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'always' becomes 'ever' (synonyms).
'about' indicates anagramming the letters.
'rome' is an anagram of 'more'.
'n'+'ever'+'more'='NEVERMORE'
Can you help me to learn more?
(Other definitions for nevermore that I've seen before include "At no time hereafter" , "as the Raven said" , "Message delivered by raven" , "not to be repeated" , "Not again (poetical)" .)