nautilus

noun nau·ti·lus \ ˈnȯ-tə-ləs , ˈnä- \

Definition of nautilus

plural nautiluses or nautili play \ˈnȯ-tə-ˌlī, -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

See nautilus defined for kids

Recent Examples of nautilus from the Web

Its spiral shape was inspired by the nautilus, the self-replicating living fossil.

— Washington Post, "Monument honoring Virginia native tribes awaits ceremony," 6 Mar. 2018
In the ocean’s depths where oxygen gets thin, the nautilus seems to be putting itself at risk by expending so much effort on movement.

— New York Times, "The Chambered Nautilus Is the Ocean’s Most Efficient Jet Engine," 23 Feb. 2018
The nautilus has not populated the earth as extensively as the ammonite, which broke into thousands of species, Famoso said.

— kyle spurr, The Christian Science Monitor, "Girl finds 65 million year old fossil in Oregon field," 19 Mar. 2018
Adding weight to this theory is evidence that nautiluses, a closely related shelled cephalopod known to be less intelligent, don’t possess the same editing capabilities.

— nathaniel scharping, Discover Magazine, "Octopuses Can Stray From Their DNA," 24 Jan. 2018
One looked like a nautilus shell, with thick dots marking points along its swirl.

— sam anderson, New York Times, "The Mind of John McPhee," 28 Sep. 2017
And while this feature persists in the nautilus and a few other remaining species, subsequent cephalopods eventually shed their shells.

— colin dickey, New Republic, "When Squid Ruled the Earth," 21 Sep. 2017
Other cephalopods, like octopuses and nautiluses, lack S-crystallin lens proteins.

— kai sinclair, Science | AAAS, "Watch the secret to a squid’s crystal clear underwater vision," 10 Aug. 2017
And, despite its continued association with all things water, there are some who claim that nautilus motifs are bad luck, since the nautilus typically sinks to the depths of the ocean.

— ayesha khan, CNT, "Secrets of a Cruise Ship Designer," 21 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'nautilus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.