Report Abuse. A dormant volcano is a volcano which is not currently active (that is, not erupting nor showing signs of unrest), but is believed to be still capable of erupting. This contrasts with an extinct volcano, where it is believed that no eruptions will occur for the foreseeable future.n practice, it is often impossible to distinguish between a dormant and an extinct volcano and several volcanoes thought to be extinct have subsequently re-erupted. Volcanoes can be dormant for hundreds or thousands of years and, due to the lack of eruptions, are usually eroded and worn down.