- belonging or pertaining to the class Echinoidea, comprising mainly sea urchins and sand dollars.
- any echinoderm of the Echinoidea.
Origin of echinoid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for echinoid
A pair of ciliated epaulettes on each side of and behind the ciliated ring is very characteristic of some Echinoid larv.The Works of Francis Maitland Balfour, Volume II (of 4)
Francis Maitland Balfour
The rows of plates in an Echinoid which are not perforated for the emission of the "tube-feet."The Ancient Life History of the Earth
Henry Alleyne Nicholson
- any of the echinoderms constituting the class Echinoidea, typically having a rigid ovoid body. The class includes the sea urchins and sand dollars
- of or belonging to this class
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012