Stromboli Spillage is a geological phenomenon that occurs when molten LAVA from the volcano Stromboli in Italy spills over its crater rim. The term is used to describe the overflow of LAVA from the volcano, which can be seen from the nearby island of Sicily. The LAVA is usually red-hot and can reach temperatures of up to 1, 000 degrees Celsius. The LAVA spillage is a result of the intense volcanic activity at Stromboli, which has been erupting continuously since 1932. The four letter solution for this crossword is 'LAVA'.