estuary

plural estuaries · alternative archaic æstuary

1. A coastal water body where ocean tides and river water merge, resulting in a brackish water zone.

   The railway then follows the widening estuary of the river, which at high tide has the appearance of a lake, but at low water presents a rather cheerless expanse of dark mud.

   1953 February, H. A. Vallance, “To Brighton through the Shoreham Gap”, in Railway Magazine, page 82

   1 more example

   There's something special about tidal estuaries, due to the abundance of wildlife and the ever-changing scenes as the water ebbs or rises. Throw in some moody skies and filtered sunlight, and the views can resemble a painting by Turner - only you don't have to go to the National Gallery to see this, it's brought to your seat on a train.

   2020 December 2, Paul Bigland, “My weirdest and wackiest Rover yet”, in Rail, page 65

2. An ocean inlet also fed by fresh river water.

1. colloquialEstuary English

   Many of them would move to the new private housing estates springing up further east along the Thames Corridor, where they would learn to 'speak Estuary'.

   2015, Jonathan Schneer, The Thames: England's River