abate
afflict
attenuate
beat
blunt
bugger
burn out
cramp
cripple
damp
dampen
de-energize
deaden
derange
devitalize
disable
disenable
disorder
do in
do up
drain
dull
enervate
enfeeble
eviscerate
exhaust
extenuate
fag
fag out
fatigue
flag
frazzle
gruel
hamstring
harass
hors de combat
hospitalize
hurt
inactivate
incapacitate
indispose
invalid
jade
kibosh
knock out
knock up
lame
lay low
weaken
emaciate
macerate
waste
debilitated
debilitates
debilitating
debile
debilitation
debility
adverse
allergic
cardiovascular
contagious
corrosive
curable
degenerative
detrimental
devastate
febrile
gastrointestinal
harmful
hazardous
inflammatory
life-threatening
neurological
preventable
psychosomatic
rheumatic
traumatic
unbearable
facilitate
rehabilitate