n. pl. os·tra·ca (-kə)
An inscribed potsherd.
[Greek ostrakon, shell; see ost- in the Appendix of Indo-European roots.]
(click for a larger image)ostracon
late 5th-century bc ostracon with the name of Themistocles Phrearrhios
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.