Adjustable spanner (6)
I believe the answer is:
wrench
'adjustable spanner' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for wrench that I've seen before include "Violent twist - (adjustable) spanner" , "Tear away" , "Sprain - difficult parting" , "Yank" , "Kind of spanner or severe twist" .)