Pillager's tool picked up with hesitation (6)
I believe the answer is:
looter
'pillager's' is the definition.
(synonyms)
'tool picked up with hesitation' is the wordplay.
'picked up' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'hesitation' becomes 'er' (sound made while hesitating - um, er).
'tool' reversed gives 'loot'.
'loot'+'er'='LOOTER'
(Other definitions for looter that I've seen before include "criminal" , "Pillager, plunderer" , "robber" , "Thief during unrest" , "Stealer during riot" .)