Found 2 items, similar to sea urchin.
English → English (WordNet) Definition: sea urchin sea urchin n : shallow-water echinoderms having soft bodies enclosed in thin spiny globular shells
English → English (gcide) Definition: Sea urchin Sea urchin \Sea“ ur”chin\ (Zo["o]l.) Any one of numerous species of echinoderms of the order Echinoidea. Note: When living they are covered with movable spines which are often long and sharp. [1913 Webster]