Source : Webster's Revised Unabridged Dictionary (1913)

Solfatara \Sol`fa*ta"ra\, n.[It., from solfo brimstone, sulphur,
   L. sulfur, E. sulphur.] (Geol.)
   A volcanic area or vent which yields only sulphur vapors,
   steam, and the like. It represents the stages of the volcanic
   activity.