Definition that contains urchin
- test a hard outer covering as of some amoebas and sea urchins
- ragamuffin a dirty shabbily clothed urchin
- order spatangoida heart-shaped sea urchins
- spatangoida heart-shaped sea urchins
- exocycloida flat sea urchins
- echinoidea sea urchins and sand dollars
- phylum echinodermata radially symmetrical marine invertebrates including e.g. starfish and sea urchins and sea cucumbers
- tube foot tentacular tubular process of most echinoderms (starfish and sea urchins and holothurians) having a sucker at the end and used for e.g. locomotion and respiration
- class echinoidea sea urchins and sand dollars
- heart urchin sea urchin having a heart-shaped body in a rigid spiny shell