Recedes, declines (4)
I believe the answer is:
ebbs
I believe this is a double definition.
'recedes' is the first definition.
(ebbing is a kind of receding)
'declines' is the second definition.
(I know this)
(Other definitions for ebbs that I've seen before include "Goes out like tide" , "Flows back - declines" , "fades away" , "Declines gradually" , "Flows back or recedes" .)