Obtain by force (6)
I believe the answer is:
extort
'obtain by force' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for extort that I've seen before include "To get through compulsion" , "Obtain by force or intimidation" , "Obtain by coercion or intimidation" , "Extract money with menances" , "Wring (money) out (by violence, etc)" .)