a volcano that has not erupted for many years.
Literally, "sleeping." The term is used to describe a volcano which is presently inactive but which may erupt again. Most of the major Cascade volcanoes are believed to be dormant rather than extinct.
An active volcano that is in repose (quiescence) but is expected to erupt in the future.
A volcano that has not erupted for hundreds to thousands of years but does have the potential to erupt again in the future.
A dormant volcano is a volcano that is not active now, but may erupt in the future.
A dormant volcano is a volcano which is not currently erupting, but is believed to still be capable of erupting in the future. This contrasts with an extinct volcano, where it is believed that no future eruptions will ever occur.