nautilus

definition: cephalopod of the Indian and Pacific oceans having a spiral shell with pale pearly partitions
example:
speech part: noun
synonyms: chambered nautilus
definition: cephalopod mollusk of warm seas whose females have delicate papery spiral shells
example:
speech part: noun
synonyms: paper nautilus
definition: a submarine that is propelled by nuclear power
example:
speech part: noun
synonyms: nuclear submarine nuclear-powered submarine

How nautilus is being used?