Meaning of hydrothermal vent

hy'drother'mal vent'

Pronunciation: [key]
— Oceanog., Geol. Oceanog.,Geol.
  1. 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.