n. pl. nau·ti·lus·es or nau·ti·li (nôtl-ī′)
1. Any of several cephalopod mollusks of the family Nautilidae of the Indian and Pacific Oceans, especially Nautilus pompilius, having numerous slender tentacles and an external coiled pearly shell divided into air-filled chambers. Also called chambered nautilus, pearly nautilus.
2. The paper nautilus.
[Latin, from Greek nautilos, sailor, nautilus, from nautēs, mariner, from naus, ship; see nāu- in the Appendix of Indo-European roots.]
(click for a larger image)nautilus
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