Edward backed our diversion (6)
I believe the answer is:
detour
'diversion' is the definition.
(thesaurus)
'edward backed our' is the wordplay.
'edward' becomes 'ted'.
'backed' is a reversal indicator.
'ted' written backwards gives 'det'.
'det'+'our'='DETOUR'
(Other definitions for detour that I've seen before include "Temporary route" , "A way around or deviation from intended route" , "Temporary roundabout way" , "Deviation from direct course" , "Deviation from the usual route" .)