Touch guards with armed robber (6)
I believe the answer is:
bandit
'armed robber' is the definition.
(I've seen this before)
'touch guards with' is the wordplay.
'touch' becomes 'bit' (I've seen this in another clue).
'guards' indicates putting letters inside (inserted letters are guarded).
'with' becomes 'and'.
'bit' going around 'and' is 'BANDIT'.
(Other definitions for bandit that I've seen before include "Dan bit the robber badly" , "Highwayman" , "Thief" , "Crook" , "Violent robber" .)