A large spring or exsurgence of an underground river, generally from limestone, that varies greatly in output and is impenetrable except with diving apparatus.
Synonym, gushing spring.
ojo, ojo de agua. (Spanish.) An artesian spring in limestone regions, especially one forming a small pond; a vauclusian spring.
Watson Hiner Monroe (1970): A Glossary of Karst Terminology, Geological Survey Water-supply Paper 1899-k, Library of Congress catalog-card No. 75-607530 DOI online