Rolling Rock is a type of beer that has been produced by the Latrobe Brewing Company since 1939. The term Rolling Rock is derived from the three crossword solutions: LAVA (4 letters), MAGMA (5 letters), and Molten LAVA (10 letters). LAVA is molten rock that is expelled from a volcano during an eruption. MAGMA is molten rock that is located beneath the Earth's surface. Molten LAVA is the liquid form of LAVA that is expelled from a volcano.