sea urchin

noun

: a small sea animal that lives on the ocean floor and is covered in sharp spines

Full Definition of SEA URCHIN

: any of numerous echinoderms (class Echinoidea) that are usually enclosed in thin brittle globular tests covered with movable spines

See sea urchin defined for English-language learners

See sea urchin defined for kids

1591

SEA URCHIN Defined for Kids

noun

: a small sea animal that is related to the starfish, lives on the sea bottom, and is enclosed in a roundish shell covered with spines that can move

Next Word in the Dictionary: sea urchin cactusPrevious Word in the Dictionary: sea unicornAll Words Near: sea urchin

What made you want to look up sea urchin? Please tell us where you read or heard it (including the quote, if possible).

Put-downs with flair

How to use a word that (literally) drives some people nuts.

Test your vocab with our fun, fast game

Ailurophobia, and 9 other unusual fears