decreasing
at rest
calm
catabasis
cloistered
collapse
coming apart
contractive
cool
cracking
crash
crumbling
decadent
deceleration
declension
decline
decline and fall
declining
decrescendo
decrescent
degenerate
deliquescent
deteriorating
diminishing
diminuendo
disintegrating
dive
downtrend
downturn
draining
drooping
drop
dwindling away
dying
ebb
ebbing
effete
even-tenored
fading
failing
fall
falling
flagging
fragmenting
going to pieces
halcyon
hushed
impassive
isolated
languishing
kindling
pindling
rekindling
swindling