Rogue tied soldiers up (7)
I believe the answer is:
bounder
'rogue' is the definition.
(thesaurus)
'tied soldiers up' is the wordplay.
'tied' becomes 'bound' ('bind' can be a synonym of 'tie').
'soldiers' becomes 're' (Royal Engineers).
'up' says the letters should be written backwards (in down clue: letters go upwards).
're' back-to-front is 'er'.
'bound'+'er'='BOUNDER'
(Other definitions for bounder that I've seen before include "despicable man" , "Dishonourable man (dated colloq.)" , "The skipper" , "A hop-along cad?" , "Untrustworthy type (once)" .)