echinoderms Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. A group of marine animals that have hard, spiny coverings. Example Sentence Echinoderms are a group of marine animals that include starfish and sea urchins. Synonyms sea stars; sea urchins; sand dollars Antonyms mammals; birds Hear It! Say It! Write It! echinoderms Switch to cursive Start Share with your friends:
