Tridacna

noun

1. type genus of the family Tridacnidae: giant clams

   noun.animal

   Synonyms genus tridacna

   Source: WordNet 3.0

2. A genus of very large marine bivalve shells found on the coral reefs of the Indian and Pacific Oceans. One species (<i>T. gigas</i>) often weighs four or five hundred pounds, and is sometimes used for baptismal fonts. Called also <i>paw shell</i>, and <i>fountain shell</i>.

   noun

   Source: webster1913