From Longman Dictionary of Contemporary Englishsea urchinˈsea ˌurchin noun [countable] HBAa small round sea animal with a hard shell covered in sharp points
Examples from the Corpus
sea urchin• Thousands of fertilized sea urchin eggs, starfish and blue clams returned to Earth with the astronauts.• Oyster soup with sliced sea urchin is the other original Loiseau signature dish.• But please, hold the sea urchin. 