noun
HistoryIn ancient Greece: a division of the army comprising fifty men.
Origin
Early 19th century; earliest use found in William Mitford (1744–1827), historian of ancient Greece. From ancient Greek πεντηκοστύς (plural πεντηκοστύες) a number or company of fifty from πεντηκοστός fiftieth.
Are You Learning English? Here Are Our Top English Tips