A geyser is a natural phenomenon that occurs when hot water and STEAM are ejected from the ground. It is usually caused by the presence of underground magma or hot springs. The term 'geyser' comes from the Icelandic word 'geysir, ' which means 'to gush.' The crossword solutions for the term GEYSER are SPRING (6 letters), SOURCE (6 letters), FOUNTAIN (8 letters), and STEAM (5 letters). A SPRING is a SOURCE of water that flows naturally from the ground, while a SOURCE is the origin of something. A FOUNTAIN is a structure that shoots water into the air, and STEAM is the gaseous form of water. All of these terms are related to geysers, as they are all associated with the natural phenomenon of hot water and STEAM being ejected from the ground.