The ancient Greek vessel called a pithos in Pandora’s story is a large earthenware jar. Hesiod’s Greek text uses pithos, a term for a substantial storage container used for products such as grain or wine.
The phrase “Pandora’s box” became standard because the Renaissance humanist Erasmus translated or popularized the Latin expression pyxis, meaning box, in the sixteenth century. Artists and writers then spread the compact box image, even though the earliest source describes a jar.
A pithos could be taller than a person and was often partly buried for stability and cool storage. Calling it a jar preserves the ancient wording and helps distinguish the original myth from later European adaptations. The modern idiom still means an action that unleashes unexpected problems.