1. the wide part of a river where it meets the ocean and is affected by tides
Usage: plural of estuary; typically found in coastal geography and environmental science

Examples

• Many estuaries around the world are home to diverse wildlife and fish species.
• The estuary of the Thames River is one of the most important ports in Europe.
• Estuaries provide crucial habitats for migratory birds and marine life.
• Salt marshes in estuaries help filter water and protect coastal areas from storms.
• The Chesapeake Bay is the largest estuary in the United States.
• Estuaries are where freshwater from rivers mixes with saltwater from the ocean.