estuaries

Noun

estuary (plural estuaries)

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

See all 3 meanings of estuary