Source : Webster's Revised Unabridged Dictionary (1913)

Vulcanology \Vul`can*ol"o*gy\, n. [See {Vulcan}, and {-logy}.]
   The science which treats of phenomena due to plutonic action,
   as in volcanoes, hot springs, etc. [R.]

Source : WordNet®

vulcanology
     n : the branch of geology that studies volcanoes [syn: {volcanology}]