a volcanic vent or fissure giving off only vapors, esp. sulfurous gases
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'solfatara'It < solfo, sulfur < L sulfur