- a genus of giant clams inhabiting reefs in the South Pacific, attaining a diameter of 4 feet (1.2 meters) or more, and weighing over 500 pounds (227 kg).
Origin of Tridacna
1770–80; < New Latin, noun use of feminine of Latin tridacnus requiring three bites < Greek trídaknos, equivalent to tri- tri- + dákn(ein) to bite + -os adj. suffix
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for tridacna
Tridacna is distinguished from Hippopus by the large opening in the hinge.A Conchological Manual
George Brettingham Sowerby
A tridacna spread its jaws before his steps so that he nearly plunged into the deadly springtrap of the deep.Where the Pavement Ends
The former is supposed to have originated from the tridacna shell, the latter from the taro.Two Years with the Natives in the Western Pacific
The shell of the Tridacna gigas is the largest anywhere known.
The valves of Tridacna gigas are sometimes found a yard and a half in length, and weighing five hundred pounds.The Ocean World: