noun
bay
BAY/beɪ/
A broad inlet of water partly enclosed by land.
The bay opens between two curving arms of land.
Etymology
Latin baia already named a coastal inlet. The English sense preserves that geographical idea: a recess in the shoreline, with land partly surrounding the water.
In context
this estuary is a partially enclosed coastal body of brackish water now you may have a question well it is called a bay