nautilus

noun

nau·​ti·​lus ˈnȯ-tə-ləs How to pronounce nautilus (audio)
ˈnä-
plural nautiluses or nautili ˈnȯ-tə-ˌlī How to pronounce nautilus (audio)
-ˌlē, 
ˈnä-
1
: any of a genus (Nautilus) of cephalopod mollusks of the South Pacific and Indian oceans with a spiral chambered shell that is pearly on the inside

called also chambered nautilus

2
: paper nautilus

Illustration of nautilus

Illustration of nautilus
  • nautilus 1

Examples of nautilus in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The nautilus draws fluid in and out of those chambers to sink or float in the water column. — Amanda Kooser, Forbes, 6 Dec. 2024 Ammonites used the chambers in their shells to control buoyancy, much like the modern nautilus. — Torben Rick, The Conversation, 18 June 2026 But later research showed that decay processes can give a similar appearance in the eyes of cephalopods, like squid or nautiluses. — Cody Cottier, Discover Magazine, 8 July 2025 New research has reclassified the specimen as a relative of the nautilus, a cephalopod with both tentacles and a shell. — Samantha Agate, Fort Worth Star-Telegram, 23 Apr. 2026 See All Example Sentences for nautilus

Word History

Etymology

New Latin, from Latin, paper nautilus, from Greek nautilos, literally, sailor, from naus ship

First Known Use

1601, in the meaning defined at sense 1

Time Traveler
The first known use of nautilus was in 1601

Phrases Containing nautilus

Browse Nearby Words

Nautiloidea
nautilus
Nauvoo
See all Nearby Words

Cite this Entry

“Nautilus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nautilus. Accessed 7 Jul. 2026.

Copy Citation

Kids Definition

nautilus

noun
nau·​ti·​lus ˈnȯt-ᵊl-əs How to pronounce nautilus (audio)
ˈnät-
plural nautiluses or nautili -ᵊl-ˌī How to pronounce nautilus (audio)
-ˌē
1
: any of a genus of mollusks of the South Pacific and Indian oceans that are cephalopods and have a spiral chambered shell that is pearly on the inside

called also chambered nautilus

2
: paper nautilus

More from Merriam-Webster on nautilus

Nglish: Translation of nautilus for Spanish Speakers

Britannica.com: Encyclopedia article about nautilus

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

Is that lie 'bald-faced' or 'bold-faced'?

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Commonly Misspelled Words

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)
See More

Popular in Wordplay

See More

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

One-Word Oxymorons: Bittersweet, Spendthrift, and More

Ten Words Ending with a Silent ‘T’

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

Is that lie 'bald-faced' or 'bold-faced'?

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
hangman letters and game
Hangman Lightning Round Figure out which word fits in the blanks.
See All