River's end is a term used to describe the point where a river meets the sea. The crossword solutions for this term are DELTA (5 letters), MOUTH (5 letters), and ESTUARY (7 letters). A DELTA is a triangular area of sediment deposited at the MOUTH of a river, while the MOUTH of a river is the point where the river flows into a larger body of water. An ESTUARY is a partially enclosed coastal body of water where fresh water from rivers and streams mixes with salt water from the ocean.