Wiktionary
n. (context UK English) An appointment in the army, the senior warrant officer in a company, usually held by a warrant officer class 2.
Wikipedia
The company sergeant major (CSM) is the senior non-commissioned soldier of a company in the armies of many Commonwealth countries, responsible for administration, standards and discipline. In combat, his prime responsibility is the supply of ammunition to the company. He also oversees the distribution of other supplies, such as water or food, although that responsibility is mainly that of the company quartermaster sergeant (CQMS), and evacuating the wounded and collecting prisoners of war.
For military units of the same level as a company, the equivalent may be squadron sergeant major (SSM) or battery sergeant major (BSM). In the Household Cavalry, squadron corporal major (SCM) is the equivalent. First sergeant and kompaniefeldwebel (formerly hauptfeldwebel in the Wehrmacht and Nationale Volksarmee) are the United States Army and German Heer equivalents respectively.
Usage examples of "company sergeant major".
After almost a year there, I was posted back to Vietnam, this time replacing a 6RAR Company Sergeant Major, or CSM, who'd been evacuated home sick.
Huckfield, a studious and careful man from the north of England who had been promoted to the new rank of Company Sergeant Major, shouted forward to d'Alembord.
Watching the prince drift out of the free-fall and flip to a lithe touchdown on the padded landing area, Company Sergeant Major Eva Kosutic had to admit that she'd seen experienced spacers handle the maneuver worse.
You're not a company sergeant major in the Grenadiers now, you know.
Probably not even Witchfinder Company Sergeant Major Narker,* who held the all.
Probably not even Witchfinder Company Sergeant Major Narker,* who held the alltime record for most witches found.