Learn how to say Nautiluses correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word Nautilus:
the first nuclear-powered submarine, launched in 1954. This US navy vessel made a historic journey (1-5 August 1958) under the ice of the North Pole.
a name previously given to Robert Fulton’s ‘diving boat’ (1800), also to the fictitious submarine in Jules Verne’s Twenty Thousand Leagues under the Sea