intransitive. To flow back or recede, as the water of the sea or a tidal river: frequent in phrase, to ebb and flow. Also with away, down, off, out.

To grow less in quantity or volume. Of the sea, water: To subside, ebb. Obsolete.

Of water: To subside, ebb. Obsolete.

intransitive. Of a flood: to subside, go down. Obsolete. rare.