tridacna Meaning, Definition & Usage

  1. noun type genus of the family Tridacnidae: giant clams
    genus Tridacna.

WordNet

Tri*dac"na noun
Etymology
L., pl., a kind of oysters, fr. Gr. eaten at three bites, tri- + to bite.
Definitions
  1. (Zoöl.) A genus of very large marine bivalve shells found on the coral reefs of the Indian and Pacific Oceans. One species (T. gigas) often weighs four or five hundred pounds, and is sometimes used for baptismal fonts. Called also paw shell, and fountain shell.

Webster 1913