from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An inscribed potsherd.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A piece of pottery or stone, usually broken off from a vase or other earthenware vessel.
from The Century Dictionary and Cyclopedia
- n. In Greek antiquity, a potsherd or tile; a square plaque of terra-cotta on which an inscription is written.
Greek ostrakon, shell; see ost- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
Ancient Greek ὄστρακον (Wiktionary)