ebb and flow
US /ˈɛb ənd ˈfloʊ/
UK /ˈɛb ənd ˈfloʊ/
1.
the recurrent or rhythmical pattern of coming and going or decline and regrowth
:
•
The ebb and flow of the tides is a natural phenomenon.
•
Life has its own ebb and flow, with good times and bad.