ostracize [M17th] In ancient Athens the people of the city would gather together every year to vote on whether an unpopular citizen should be expelled for ten years. They wrote the name of the person they wanted to send into exile on an ostrakon, a shell or fragment of pottery, and somebody who was exiled in this way was said to have been ostracized. Today a person who is ostracized is excluded from a society or group. See also oyster.