Other forms: colonels
A colonel is a commissioned military officer in the U.S. Army, Air Force, or Marines who ranks above a lieutenant colonel and below a brigadier general.
We still say colonel like the French word it comes from, coronel, which means "chief." To your ear, it probably sounds like "kernel." A colonel leads a regiment, but there are many other levels of officers, all generals, above him. Just below the colonel is the lieutenant colonel, which means colonel’s aide, and below that is the rank of major.