estuary

Etymology

From Latin aestuarium (“creek”, “estuary of a river”).

noun

1. A coastal water body where ocean tides and river water merge, resulting in a brackish water zone.
   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. December 2 2020, Paul Bigland, “My weirdest and wackiest Rover yet”, in Rail, page 65
2. An ocean inlet also fed by fresh river water.