conchoidal

adjective

con·​choi·​dal käŋ-ˈkȯi-dᵊl 

kän-

: having elevations or depressions shaped like the inside surface of a bivalve shell

conchoidally

käŋ-ˈkȯi-dᵊl-ē 

kän-

adverb

Word History

Etymology

Greek konchoeidēs like a mussel, from konchē

First Known Use

1666, in the meaning defined above