Test Tes·ta n.; pl. E. Tests L. Testae
1. Zool. The external hard or firm covering of many invertebrate animals.
Note: ☞ The test of crustaceans and insects is composed largely of chitin; in mollusks it is composed chiefly of calcium carbonate, and is called the shell.
2. Bot. The outer integument of a seed; the episperm, or spermoderm.
n : protective outer layer of seeds of flowering plants [syn: episperm,
[also: testae (pl)]