The term 'BEACH MATTER' can be solved by the four-letter word 'SAND'. SAND is a granular material composed of finely divided rock and mineral particles. It is most commonly found on beaches, deserts, and other areas where wind and water have eroded rocks and minerals over time. SAND is an important part of beach ecosystems, providing habitat for many species of animals and plants. It also helps to protect shorelines from erosion and storm damage.