A vocabulary of landscape — a landscape of words 1367 entries

ebb

EB
The ebb is the outgoing tide, the several hours between high water and low when the sea is running back out. It is not the same as low water, which is the moment the ebb stops. On a coast with any real tidal range, the ebb is a current as much as a fall in level, and in a narrow inlet or a river mouth it can run faster than a person can paddle against.
Etymology
The word is Old English and has kept its shape and meaning for well over a thousand years. It is related to the ordinary word off, and the sense they share is going away from. The figurative use came early and never left: something at a low ebb, or the ebb and flow of an argument, uses the tide as a picture of anything that has a rhythm to it.
Notes
An ebb tide against a wind blowing the other way stacks up short steep seas over a bar or in an inlet mouth, which is why local knowledge on any tidal coast is mostly knowledge of when not to be there. Slack water, the pause between ebb and flood, is the working window for crossing.