In Hesiod’s Pandora myth, the container that held the escaping evils was a pithos.
A pithos was a large ancient Greek storage jar, commonly used for grain, oil, wine, or other goods. Hesiod’s Works and Days describes Pandora opening such a vessel, not a small hinged box. The Greek word is πίθος, usually transliterated as pithos.
The familiar phrase “Pandora’s box” arose later. Renaissance humanist Erasmus used the Latin phrase pyxis Pandorae, meaning “Pandora’s box,” when discussing the myth. That wording helped replace the original image of a large jar in popular retellings.
The change is one of the best-known translation developments in classical mythology. “Pithos” identifies the vessel in the earliest surviving literary account, while “Pandora’s box” remains the standard English expression for a source of unexpected troubles.