Like many scientific terms, volcano means different things to different people. The definition should reflect the goals of the user.  Are those goals directed toward semantics or do they include the cause, the process and understanding?

Web Definitions

   Smithsonian GVN



    FEMA for Kids

    Gov’t of NZ

   Scenta UK

From Wohletz & Heiken, 1992, Volcanology and Geothermal Energy, UC Press

Is this a volcano?  How about this?  Or this?