sea urchin

noun

any echinoderm of the class Echinoidea, having a somewhat globular or discoid form, and a shell composed of many calcareous plates covered with projecting spines.
a tall evergreen shrub or small tree, Hakea laurina, of Australia, having narrow leaves and dense, globe-shaped clusters of crimson flowers with long yellow stamens.

Origin of sea urchin

First recorded in 1585–95

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for sea urchin

Historical Examples of sea urchin

A name in our northern isles for the sea-urchin, Echinus marinus.
The Sailor's Word-Book
William Henry Smyth
On my way to the front of the peninsula, I looked for “sea-urchin,” but none fell in my way.
The Boy Tar
Mayne Reid
You know, from the second lecture, what a gastrula of our sea-urchin is.
The Science and Philosophy of the Organism
Hans Driesch
The sea-urchin can thus advance with ease, and even rapidity.
The Ocean World:
Louis Figuier
The body of the sea-urchin is furnished with a species of spine.
The Ocean World:
Louis Figuier

British Dictionary definitions for sea urchin

sea urchin

noun

any echinoderm of the class Echinoidea, such as Echinus esculentus (edible sea urchin), typically having a globular body enclosed in a rigid spiny test and occurring in shallow marine waters

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