starfish Syllabification: (star·fish)Pronunciation: /ˈstärˌfiSH/Translate starfish | into French | into German | into Italian | into Spanish Definition of starfish noun (plural same or starfishes) a marine echinoderm with five or more radiating arms. The undersides of the arms bear tube feet for locomotion and, in predatory species, for opening the shells of mollusks. Class Asteroidea starfish in other Oxford dictionaries Definition of starfish in the British & World English dictionary