marine cephalopod, 1601, from L. nautilus,
in Pliny a kind of marine snail (including also squid, cuttlefish, polyps, etc.), from Gk. nautilos,
"paper nautilus," lit. "sailor," from nautes
"sailor," from naus
"ship" (see naval
). The cephalopod was formerly thought to use its webbed arms as sails.