1) Abated 2) Came back from the beach 3) Declined 4) Died down 5) Diminished 6) Drew away 7) Drew away from shore 8) Drew back 9) Dwindled 10) Dwindled away 11) Eased off 12) Fell away 13) Fell back 14) Fell gradually 15) Fell off 16) Flowed away 17) Flowed back 18) Flowed out 19) Gradually declined Found on https://www.crosswordclues.com/clue/ebbed