ebb
n. C / Un. the movement of the ocean as it flows away from the shore. It is also used to describe a time when something, like a feeling or power, becomes weaker.
n. the movement of the tide out to sea; by extension, a point or condition of decline or low intensity. Often paired with 'flow' to describe cyclical patterns.
We walked along the sand during the ebb of the tide.
The business faced a difficult period during the economic ebb of the late nineties.
The natural ebb and flow of the conversation suggested a deep, unspoken understanding between the two old friends as they sat by the fire.
From Middle English ebbe, from Old English ebba (“ebb, tide”), from Proto-West Germanic abbjā, from Proto-Germanic abjô, abjǭ, from Proto-Germanic ab (“off, away”), from Proto-Indo-European *apó. See also West Frisian ebbe, Dutch eb, German Ebbe, Danish ebbe, Old Norse efja (“countercurrent”), Old English af. More at of, off.
From Middle English ebben, from Old English ebbian, from Proto-West Germanic *abbjōn (“to ebb”).
Commonly appears in the fixed phrase 'ebb and flow' to describe rhythmic change.