Retracting scandalous information in southeast — big step forward (6)
I believe the answer is:
stride
'big step forward' is the definition.
'retracting scandalous information in southeast' is the wordplay.
'retracting' says the letters should be written backwards (I've seen 'retracted' mean this).
'scandalous information' becomes 'dirt' (I've seen this before).
'in' is an insertion indicator.
'southeast' becomes 'se' (synonyms).
'dirt' written backwards gives 'trid'.
'trid' placed into 'se' is 'STRIDE'.
(Other definitions for stride that I've seen before include "Take long paces" , "style of jazz piano" , "jazz piano-playing" , "Move with long steps" , "Long walking step" .)