The term 'overwhelming quantities' can be described by three crossword solutions: SEAS (4 letters), BARRAGES (8 letters), and FLOODTIDES (10 letters). SEAS refers to large bodies of water, such as oceans, seas, and lakes. BARRAGES are structures built to control the flow of water, often used to prevent flooding. FLOODTIDES are large amounts of water that rise quickly and cause flooding. All three terms refer to large amounts of water that can be overwhelming in quantity.