The term 'Big Apple River' is composed of two crossword solutions: Hudson (6 letters) and EAST (4 letters). Hudson refers to the Hudson River, which is a 315-mile river that flows from upstate New York through the Hudson Valley into the Atlantic Ocean. EAST refers to the EAST River, which is a tidal strait that connects Upper New York Bay on its south end to Long Island Sound on its north end. Together, the Hudson and EAST Rivers form the Big Apple River, which is a popular name for the waterway that runs through New York City.