Do wrong from start to finish (6)
I believe the answer is:
offend
'do wrong' is the definition.
(thesaurus)
'start to finish' is the wordplay.
'start' becomes 'off' (as in 'from the off').
'to finish' becomes 'end' (synonyms).
'off'+'end'='OFFEND'
'from' acts as a link.
(Other definitions for offend that I've seen before include "Cause displeasure to, bruise feelings" , "Insult - sin" , "Distress" , "Be disagreeable to" , "Be displeasing to" .)