sea urchin

noun

1. 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.
2. 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.

sea urchin

noun

1. 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

Word History and Origins

Origin of sea urchin¹

First recorded in 1585–95

Example Sentences

Not to mention, you could step on a stingray or a sea urchin.

From Los Angeles Times

The spike proteins are the little points that emerge out of the coronavirus, like spines jutting from a sea urchin, and the SARS-CoV-2 virus uses them to infect a patient's cells.

From Salon

A success at Scripps in San Diego means scientists can run experiments on painted sea urchins, potentially unlocking new discoveries in biology.

From Los Angeles Times

Ninety-five percent of Northern California’s kelp forest has been displaced by sea urchin “barrens” since the West Coast’s marine heat wave in 2014, ’15 and ’16, when water temperature averaged 7 degrees above normal.

From Los Angeles Times

“You swim through piles of dead sea urchins that until days ago were significant components of the reef.”

From Science Magazine