Pronunciation: (ôr'fish", ōr'-),[key] —n., —pl.(esp. collectively)-fish,(esp. referring to two or more kinds or species)-fish•es. any long, ribbon-shaped, silvery fish of the genus Regalecus, of deep tropical waters, having a red dorsal fin along the spine that rises to a crest, and reaching a length of 30 ft. (9 m). Also called ribbonfish.