/ Dictionary / Index H hydrothermal vent: Meaning and Definition of Find definitions for: hy'drother'mal vent' Pronunciation: [key] — Oceanog., Geol. Oceanog.,Geol. an opening on the floor of the sea from which hot, mineral-rich solutions issue. Cf. vent (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hydrothermal hydrothorax Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language