ebb and flow

ebb and flow (plural ebbs and flows)

1. The flowing out and in of the tide.
2. (figuratively) A large flowing out and in, or any waxing and waning of fortunes or activity.
   • October 29 2001, The New Yorker Online

     I want to hear the roaring ebb and flow of Broadway.

• at a low ebb

ebb and flow (third-person singular simple present ebbs and flows, present participle ebbing and flowing, simple past and past participle ebbed and flowed)

1. To alternately ebb and flow, as:
   1. (of the tides) To recede and advance.
      • c. 1595–1596 (date written), William Shakespeare, “Loues Labour’s Lost”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene iii]:

        As true we are as flesh and blood can be: / The sea will ebb and flow, heaven show his face

   2. (figuratively) To wax and wane.

• come and go