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

About the only things left in these empty zones are sea urchins.

From Science News For Students

Most significantly, the demise of important predators such as otters and sea stars has led to an explosion in the population of sea urchins, which eat kelp.

From Washington Post

Our thinking has been shaped by a few well-studied organisms and genes, like worms, flies and sea urchins.

From Quanta Magazine

As its growth slowed in the warmer water, less kelp drifted into the crevices of the reefs where sea urchins typically lurk.

From Science News

Like the barrens farther south, the remaining forests are now covered by purple sea urchins.

From Science News

I had everything from raw hamachi with sea urchin to lamb tongue.

From The Daily Beast

In the indentations, sheltered from the winds, could be traced the little perforations made by the sea-urchin.

From Project Gutenberg

The Sea-urchin can walk by moving its spines, tilting its body along from one place to another on the bed of the sea.

From Project Gutenberg

There is a great deal more to know about Five-fingers; and the Sea-urchin still has his secrets which no one can explain.

From Project Gutenberg

Another cousin of the Starfish is the Sea-urchin, a round prickly creature rather like the burr of the sweet-chestnut tree.

From Project Gutenberg

Why was it not possible to prove this fact for the eggs of the sea urchin?

From Project Gutenberg