Refers to amphorae that were filled with olive oil from the sacred trees of Athena, given as prizes in the Panathenaic Games. They were neck amphorae with a large, broad body sharply tapering downward and a relatively thin neck. The standard decoration included images of Athena on one side and the contest at which the prize was won on the other, usually in the Black-figure technique.

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300200366