sea slug

American

noun

a nudibranch.

sea slug British

noun

any of various shell-less marine gastropod molluscs, esp those of the order Nudibranchia See nudibranch

"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

sea slug Scientific

Any of various colorful marine gastropods of the suborder Nudibranchia, lacking a shell and gills but having fringelike projections that serve as respiratory organs.
Also called nudibranch

Etymology

Origin of sea slug

First recorded in 1770–80

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

sea slug

After winning plaudits across the globe for his World Cup performances with Cape Verde, goalkeeper Vozinha has another honour - with a newly discovered species of sea slug being named after him.

From BBC ● Jul. 10, 2026

According to the team, he "never realized Thecacera sesama was a new species until he consulted the sea slug expert 'Hsini Lin teacher' on Facebook."

From Science Daily ● May 27, 2026

Over the past 20 years, the team has used the institute’s underwater technology to gather more information on the sea slug.

From Los Angeles Times ● Nov. 14, 2024

A new species of sea slug has been discovered in UK waters.

From BBC ● Feb. 29, 2024

“She looked at me like I was a sea slug or something. Didn’t even answer. And then — I dunno — I just sort of came to my senses and ran for it.”

From "Harry Potter And The Goblet Of Fire" by J. K. Rowling

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023