chén fú
lit. sinking and floating
to bob up and down on water
ebb and flow
fig. rise and fall
ups and downs of fortune
vicissitudes
jiǎn tuì
to ebb
to go down
to decline
dī gǔ
valley
trough (as opposed to peaks)
fig. low point
lowest ebb
nadir of one's fortunes
tuì cháo
(of a tide) to ebb or go out
xiāo zhǎng
to ebb and rise
to decrease and then grow
luò cháo
(of a tide) to ebb or go out
gǔ dǐ
valley floor
(fig.) lowest ebb
all-time low