Myr'i-ärch, n.

noun

(mĭr’ĭ-ärk), n. [Gr. μυριάρχης, μυριάρχος, from μύριοι, ten thousand, and ἀρχός, leader, chief, from ἄρχειν, to be first, to lead.] A captain or commander of ten thousand men.