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).
OLD FAITHFUL
Meaning of OLD FAITHFUL in English
Oxford guide to British and American culture English vocabulary. Руководство по британской и американской культуре, Оксфордский английский словарь. 2005