taxiarch
An Athenian military officer commanding a certain division of an army.
historical
The Taxis of the Athenian service, like the Lochus of the Lacedæmonian, was analogous to our battalion, and the rank of the Taxiarch, its commander, as of the Lochage, was nearly that of our colonel.
Where it comes from
From Ancient Greek ταξῐαρχος (taxĭarkhos, “taxiarch”), from τάξις (táxis, “body of soldiers”) + ἀρχός (arkhós, “leader, commander”). Equivalent to taxi- + -arch.
Adapted from the Wiktionary entry taxiarch (CC BY-SA 4.0).