As capital might be gripped by congestion, I cycle (5)
I believe the answer is:
ionic
'as capital' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'gripped by congestion i cycle' is the wordplay.
'gripped by' indicates a hidden word.
'IONIC' can be found hidden inside 'congestion i cycle'.
'might be' is the link.
Can you help me to learn more?
(Other definitions for ionic that I've seen before include "Classic form of dialect" , "Like a type of column with scrolled capitals" , "Greek tongue" , "A classical order of architecture" , "Old Greek" .)