Liddell-Scott-Jones

πεντηκόνταρχος (pentēkontarchos) a commander of fifty ^G:N-N

πεντηκόνταρχος-ος, ὁ,

at Athens, commander of fifty men, serving under the τριήραρχος, [Refs 5th c.BC+] as commander of a πεντηκόντερος).

__2 generally, leader of a company of fifty, [LXX]

_{LSJ Scripture Refs: LXX.Exod.18.21}