Phone round (4)
I believe the answer is:
ring
I believe this is a double definition.
'phone' is the first definition.
('ring' can be a synonym of 'phone')
'round' is the second definition.
('ring' can be a synonym of 'round')
(Other definitions for ring that I've seen before include "Circle that's square for boxers" , "Chime" , "Wedding band" , "Form circle around" , "place for fight" .)