So good to escape gangsters (4)
I believe the answer is:
thus
'so' is the definition.
(I know that so can be written as thus)
'good to escape gangsters' is the wordplay.
'good' becomes 'g' (abbreviation).
'to escape' is a deletion indicator.
'gangsters' becomes 'thugs' (I've seen this in another clue).
'thugs' with 'g' taken out is 'THUS'.
(Other definitions for thus that I've seen before include "'So, therefore (4)'" , "In this manner" , "Shut (anag.)" , "It follows" , "as indicated" .)