Pandora's box

In Greek mythology, Pandora's box was a large jar (πιθος P"ithos") carried by Pandora. It contained the evils to be let loose on mankind. When the box was empty, hope remained. The actual evils are not specified by Hesiod.
Where the word box is from.
The word in the original text is P"ithos", which usually refers to a large container; used to store wine or other things. Such containers were also used for funerals. In the case of Pandora, this jar may have been made of clay for use as storage as in the usual sense, or, instead, of bronze metal as an unbreakable prison.
The mistranslation of P"ithos" as "box" is usually attributed to the 16th-century humanist Erasmus of Rotterdam. Erasmus is thought to have made the error when he translated Hesiod's tale of Pandora into Latin. Hesiod's P"ithos" refers to a storage jar for oil or grain. Erasmus, however, translated "pithos" into the Latin word "pyxis", meaning "box". The phrase "Pandora's box" has endured ever since. This error was further backed by Dante Gabriel Rossetti's painting "Pandora".