/
kɒŋk, 
kɒn(t)ʃ/
n.
 (pl. conchs  
/kɒŋks/
 or conches  
/ˈkɒntʃɪz/
)
   - a tropical marine mollusc with a robust spiral shell which may bear long projections and have a flared lip. 
[Strombus and other genera: many species.]
 - Architecture  the roof of a semicircular apse.
 - another term for concha.
 
Etymology
ME: from L. concha ‘shellfish, shell’, from Gk konkhē ‘mussel, cockle, or shell-like cavity’.