πεντηκόνταρχ-ος, ὁ,
at Athens, commander of fifty men, serving under the τριήραρχος, [[ 5th-6th c.BC: Xenophon Historicus “Respublica Atheniensium” 1.2, 4th c.BC: Demosthenes Orator 50.18, 19, 24 (wrongly explained by 1st-2nd c.AD: Harpocratio Grammaticus ] Refs 5th c.BC+] as commander of a πεντηκόντερος).
__2 generally, leader of a company of fifty, [[ LXX.Exo.18.21, LXX.4Ki.1.9. ] LXX]