Definitions

1. noun

A genus of salt marsh clams, particularly the Atlantic jackknife clam (Marcia rejecta) and the Atlantic petricola (Petricola pholadiformis).

“The marine biologist studied the behavior of petricola in their natural habitat.”

2. noun

A type of mussel or saltwater clam.

“The fishermen dredged up petricola from the ocean floor.”