Carry out guillotine (7)
I believe the answer is:
execute
This clue is a double definition.
'carry out' is the first definition.
('execute' can be a synonym of 'carry out')
'guillotine' is the second definition.
(I've seen this before)
(Other definitions for execute that I've seen before include "Put to death or carry out, say plan" , "Finish off" , "Carry into effect" , "Inflict capital punishment upon" , "Put (plan) into effect; kill (a condemned person)" .)