Adjective: echinoid 'e-ki,noyd
- Pertaining to or characteristic of the Echinoidea, a class of marine animals including sea urchins and sand dollars
"The echinoid skeleton has a distinctive five-fold symmetry"
- Any marine animal of the class Echinoidea, including sea urchins and sand dollars
"The echinoid's spiny exterior provides protection from predators"
Derived forms: echinoids
Encyclopedia: Echinoid