to decrease and then increase, as with tides; a decrease followed by an increase, as with tides. The fortunes of the major political parties tend to ebb and flow over time.The ebb and flow of democracy through history is a fascinating subject.
A decline and increase, constant fluctuations. For example, He was fascinated by the ebb and flow of the Church's influence over the centuries. This expression alludes to the inward and outward movement of ocean tides. [Late 1500s]