conch

noun (plural conchs /kɒŋks/ or conches /ˈkɒntʃɪz/)

• 1 (also conch shell) a tropical marine mollusc with a robust spiral shell which may bear long projections and have a flared lip.

  • Strombus and other genera, family Strombidae, class Gastropoda
• a conch shell blown like a trumpet to produce a hollow-sounding musical note, often depicted as played by Tritons.

• 2 Architecture the roof of a semicircular apse, shaped like half a dome.

• 3another term for concha.