a phylum of marine invertebrates which includes starfishes, sea urchins, brittlestars, crinoids, and sea cucumbers. They have fivefold radial symmetry, a calcareous skeleton, and tube feet operated by fluid pressure.
modern Latin (plural), from Greek ekhinos 'hedgehog, sea urchin' + derma 'skin'
Echinodermata in other Oxford dictionaries
Definition of Echinodermata in the US English dictionary