any cephalopod mollusc of the genus Argonauta, esp A. argo, of warm and tropical seas, having a papery external spiral shell: order Octopoda (octopods)
Also called: argonaut. Compare pearly nautilus
paper nautilus in American English
1.
any of a genus (Argonauta) of small, squidlike octopods: the female secretes a large, frail, paperlike shell to protect her eggs until they hatch; argonaut