ria

noun1

1. •
   A narrow inlet of the sea formed by a flooded unglaciated river valley.

   • Flinders had advised Baudin to stop in Port Jackson (the ria of what is now Sydney) when in need of refreshment […]. — 2020

noun5

1. •
   Initialism of registered investment adviser.
2. •
   Initialism of rich Internet application.
3. •
   Initialism of radioimmunoassay.
4. •
   Initialism of Regulatory Impact Assessment.
5. •
   Initialism of Reactivity-Initiated Accident.