Origin: L, from testa the shell of shellfish, or of testaceous animals.
1. (Science: zoology) A genus of tortoises which formerly included a large number of diverse forms, but is now restricted to certain terrestrial species, such as the European land tortoise (Testudo Graeca) and the gopher of the southern united states.
2. A cover or screen which a body of troops formed with their shields or targets, by holding them over their heads when standing close to each other. This cover resembled the back of a tortoise, and served to shelter the men from darts, stones, and other missiles. A similar defense was sometimes formed of boards, and moved on wheels.
3. A kind of musical instrument. A species of lyre; so called in allusion to the lyre of mercury, fabled to have been made of the shell of a tortoise.