A helot was a serf in ancient Sparta, a person who had to work on land owned by the state. Helots were badly mistreated by their Spartan masters.
In addition to agricultural work, helots were often assigned to do household work for individual Spartans, though they were considered the state's property. Unlike slaves in other parts of ancient Greece, helots lived in their own family groups and had a little more autonomy. They outnumbered the Spartans, though, and were kept in line by being physically mistreated and even killed. There may be an etymological connection between helot and the Greek halonai, "be captured or conquered."