Beheading puts an end to troubles (4)
I believe the answer is:
ills
'troubles' is the definition.
('ill' can be a synonym of 'trouble')
'beheading puts an end to' is the wordplay.
'beheading' means to remove the first letter.
'puts an end to' becomes 'kills' ('kill' can be a synonym of 'put an end to').
'kills' with its initial letter taken off is 'ILLS'.
(Other definitions for ills that I've seen before include "Ailments, misfortunes" , "Evils or sicknesses" , "Troubles" , "complaints" , "Sicknesses or misfortunes" .)