a nautilus

a lamp shell, lingulate brachiopod of the family Lingulidae

lampshell excluding the lingulate brachiopods (Articulata)

blood cockle, blood clam (an Asian species of bivalve resembling the cockle) (Tegillarca granosa)

a Japanese cockle, an egg cockle: an edible marine bivalve mollusc of family Cardiidae, species Fulvia mutica

Kyūjitai form of 貝殻: shell; seashell

a Triton's trumpet (Charonia tritonis) shell used in ancient times as a horn to signal troop movements

state of emergency (governmental decree)

foreign country

outside of one's field of expertise