noun
geoduck; Pacific geoduck
Refers specifically to the species Panopea generosa, a large saltwater clam native to the Pacific coast of North America. In Japanese, the katakana name is standard.
アメリカナミガイは北米の太平洋岸に生息する大きな二枚貝です。
The geoduck is a large bivalve that lives on the Pacific coast of North America.
寿司ネタとしてアメリカナミガイが使われることもある。
Geoduck is sometimes used as a sushi topping.
ミルガイ (Tresus keenae) is a similar large clam found in Japan, while アメリカナミガイ is the North American geoduck.
The name is a combination of アメリカ (America) and 波貝 (なみがい, 'wave shell'), referring to a large clam from North America. The exact derivation of 波貝 is uncertain, but it likely describes a clam associated with waves or coastal waters.