Meaning

noun a commissioned military officer in the United States Army or Air Force or Marines who ranks above a lieutenant colonel and below a brigadier general

originFirst attested in the 1540s, from Middle French coronnel, from Old Italian colonnello (“the officer of a small company of soldiers (column) that marched at the head of a regiment”), from compagnia colonnella (“little column company”), from Latin columna (“pillar”), originally a collateral form of columen, contraction culmen (“a pillar, top, crown, summit”), o-grade form from a Proto-Indo-European…

Etymology from Wiktionary, CC BY-SA 3.0