The crossword solution for the term 'LAVA, FOR ONE' is 'SOAP'. Lava is a molten rock that is expelled from a volcano during an eruption. It is composed of various minerals and gases and is usually very hot. When it cools, it forms a solid rock known as basalt. Lava can also be used to make SOAP, which is a cleansing agent made from fats or oils combined with an alkali such as sodium hydroxide. SOAP is used to remove dirt, oil, and other impurities from the skin.