abatement
allayment
alleviation
arrest
assuagement
attenuation
attrition
blunting
calming
check
damping
deadening
debilitation
deceleration
delay
demulsion
detention
devitalization
dilution
diminution
drag
dulcification
dulling
ease-off
ease-up
easing
effemination
enervation
enfeeblement
evisceration
exhaustion
extenuation
falling-off
fatigue
flagging
holdup
hushing
inanition
lag
languishment
leniency
lessening
letdown
letup
lightening
loosening
lulling
minus acceleration
mitigation
modulation
weakening
thaw
blackening