• WordNet 3.6
    • n Tridacna type genus of the family Tridacnidae: giant clams
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Webster's Revised Unabridged Dictionary
  • Interesting fact: The tridacna clam can grow up to four feet long and weigh up to 500 pounds
    • n Tridacna (Zoöl) A genus of very large marine bivalve shells found on the coral reefs of the Indian and Pacific Oceans. One species (Tridacna gigas) often weighs four or five hundred pounds, and is sometimes used for baptismal fonts. Called also paw shell, and fountain shell.
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Century Dictionary and Cyclopedia
    • n Tridacna A genus of inequilateral equivalve bivalve mollusks, forming the type of the family Tridacnidæ. The margin is deeply waved and indented, the opposite sides fitting into each other. T. gigas, the largest bivalve shell known, attains a length of 2 or 3 feet and a weight of 500 pounds or more. The animal may weigh 20 pounds or more. It is a native of the East Indian seas, and is edible. The great valves are used for various purposes, as for baptismal fonts, as receptacles for holy water, and, it is alleged, as babies' bath-tubs. The substance of the shell is extremely hard, and calcification progresses until almost every trace of organic structure is obliterated. Pieces of the shell weighing 7 or 8 pounds are used by the natives of the Caroline Islands for axes. The other species of the genus, as T. squamosa and T. crocea, are much smaller. Also called Pelex. See also cut under Tridacnidæ.
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Chambers's Twentieth Century Dictionary
    • n Tridacna trī-dak′na a genus of bivalves, the giant clam, without the shell weighing 20 lb., with the shell so much even as 500 lb.
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Webster's Revised Unabridged Dictionary
L., pl., a kind of oysters, fr. Gr. eaten at three bites, tri- + to bite
Chambers's Twentieth Century Dictionary
Gr. treis, three, daknein, to bite.


In literature:

Cockles (Tridacna), 284, 295, 306.
"Captain Cook's Journal During the First Voyage Round the World" by James Cook
It was found imbedded in the seaweed and spongy-like substance that covers the Tridacna squamosa.
"Narrative of a Survey of the Intertropical and Western Coasts of Australia] [Volume 2 of 2]" by Phillip Parker King
Tridacna 7 Indian and Pacific Oceans, Chinese Seas.
"Sea-Weeds, Shells and Fossils" by Peter Gray