KO
bugger
call off
cancel
complete
cripple
de-energize
debilitate
delete
disable
disenable
dispose of
drain
drop the curtain
end off
enfeeble
expunge
extinguish
finalize
finish
fold up
get it over
get over with
get through with
give the quietus
hamstring
hors de combat
inactivate
incapacitate
kayo
kill
knock out
lame
maim
nonsense
perfect
polish off
put
put paid to
queer
queer the works
sabotage
scrag
shoot down
spike
stuff
style
unfit
weaken
wing
forbid
foreclose
forestall
preclude
prevent
embargo
stay
kiboshed