geyseran underground hot spring that periodically erupts a column of water and steamOld Faithful is a famous geyser in Yellowstone that erupts approximately every 90 minutes.NoteOld Faithful is a famous geyser in Yellowstone that erupts approximately every 90 minutes.Elon.io is an online learning platformWe have an entire course teaching TOEFL Academic Vocabulary grammar and vocabulary.Start learning TOEFL Academic Vocabulary now