Old Faithful

Từ điển Oxford Advanced Learner 8th

Old Faithful [Old Faithful] BrE NAmE
a famous US ↑geyser (= an underground hot spring that shoots water or steam up into the air) in ↑Yellowstone National Park. It is a popular tourist attraction. Approximately once an hour it shoots hot water and steam into the air to a height of about 150 feet/46 metres.