Road regularly cut off by phone: on a line to centre? (6)
I believe the answer is:
radial
'line to centre?' is the definition.
I can't judge whether this defines the answer.
'road regularly cut off by phone on a' is the wordplay.
'road' becomes 'rd' (abbreviation for road).
'regularly cut off by phone' becomes 'ial' (I can't explain this - if you can you should give a lot more credence to this answer).
'on' is an insertion indicator (as in clothing 'on' a person).
'rd'+'ial'='rdial'
'rdial' placed around 'a' is 'RADIAL'.
Can you help me to learn more?
(Other definitions for radial that I've seen before include "tread on it" , "Set out as wheel spokes" , "Moving out from the centre" , "Having spokes that branch out from a centre" , "Sort of tyre" .)