Sally picked up a drawing pin (6)
I believe the answer is:
attack
'sally' is the definition.
(thesaurus)
'picked up a drawing pin' is the wordplay.
'picked up' says the letters should be written backwards.
'a drawing' becomes 'ta' (I can't justify this - if you can you should give a lot more credence to this answer).
'pin' becomes 'tack' (I've seen this before).
'ta' in reverse letter order is 'at'.
'at'+'tack'='ATTACK'
(Other definitions for attack that I've seen before include "Brownish pigment" , "Start a fight or criticise strongly" , "Pitch into" , "Launch an offensive" , "An assault or onslaught" .)