The Greek word pithos names the large jar or storage vessel in the original Pandora myth. Hesiod’s account uses the term pithos, while the familiar English expression “Pandora’s box” developed later through translation and tradition.
A pithos was a large ceramic container used in the ancient Greek world for storing commodities such as grain, oil, or wine. It was generally much larger than an ordinary household jar and could be kept partly buried for stability and temperature control.
The change from jar to box is commonly connected with the Latin tradition and the Renaissance humanist Erasmus. His influential Latin rendering used the word pyxis, meaning a box or container, helping establish the wording that became standard in many European languages.
This does not mean the English phrase is meaningless or wholly separate from the Greek story. It is the conventional name of the myth. However, readers studying Hesiod often distinguish the original pithos from the later “box” of popular culture.