noun
swimming crab; Portunus trituberculatus
Refers specifically to the swimming crab species Portunus trituberculatus, commonly eaten in Japan. The word is usually written in kana.
See also: 渡蟹
ガザミは味噌汁に入れると美味しい。
Swimming crab is delicious in miso soup.
市場で活きのいいガザミを買った。
I bought some lively swimming crabs at the market.
A broader term for swimming crabs (family Portunidae); ガザミ is a specific species within this group.
The origin is uncertain; the word is native Japanese. The kanji 蝤蛑 are rare and obsolete.