sea urchin
sea-urchin的词性:n.(名词)
1. Any of various echinoderms of the class Echinoidea, having a soft body enclosed in a round, symmetrical, calcareous shell covered with long spines.海胆:任一种棘皮纲的棘皮动物,具有被圆形对称的螺旋状贝壳包含的柔软躯体,贝壳表面布满棘刺