Telephoning round, perhaps (7)
I believe the answer is:
ringing
'telephoning' is the definition.
('ring' can be a synonym of 'telephone')
'round perhaps' is the wordplay.
'round' becomes 'ring' (synonyms).
'perhaps' becomes 'ing' (I can't explain this - if you can you should believe this answer much more).
'ring'+'ing'='RINGING'
Can you help me to learn more?
(Other definitions for ringing that I've seen before include "Pealing" , "Resonant; forceful" , "Resonant; phoning" , "Chiming" , "Having resonant sound" .)