Use some pretext or try to obtain by force (6)
I believe the answer is:
extort
'obtain by force' is the definition.
(I've seen this before)
'use some pretext or try' is the wordplay.
'use some' says the answer is hidden in the clue (I've seen this in other clues).
'EXTORT' can be found hidden inside 'pretext or try'.
'to' acts as a link.
(Other definitions for extort that I've seen before include "Obtain by force or intimidation" , "Obtain by intimidation, say money" , "Obtain (money etc) by force" , "Gain money by force" , "fleece" .)