The crossword solution for the term 'SLOWLY LEAK' is 'SEEP'. Seepage is the slow movement of liquid through a porous material, such as soil or rock. It is a common occurrence in nature, and can be caused by a variety of factors, including gravity, pressure, and chemical reactions. Seepage can also occur in man-made structures, such as dams and levees, and can lead to structural damage if not properly managed.