Twist violently (6)
I believe the answer is:
wrench
'twist violently' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for wrench that I've seen before include "Sort of spanner - twist it" , "Spanner-like tool" , "Tear away" , "Emotional pain felt on parting" , "Violent twist - (adjustable) spanner" .)