The Collaborative International Dictionary
Volcanist
Volcanist \Vol"can*ist\, n. [Cf. F. volcaniste, vulcaniste.]
One versed in the history and phenomena of volcanoes.
One who believes in the igneous, as opposed to the aqueous, origin of the rocks of the earth's crust; a vulcanist. Cf. Neptunist.
Wiktionary
volcanist
n. (context volcanology English) Someone interested in volcanism and volcanology the study of volcanoes.