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

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

When Omri Bronstein began to trace the advance of a mysterious sea urchin plague down the Gulf of Aqaba in early 2023, he was ahead of the tide.

From Science Magazine

A recent boom in the purple sea urchin population off the southern Oregon Coast appears to have had an indirect and negative impact on the gray whales that usually forage in the region, a new study shows.

From Science Daily