"master gunnery sergeant." YourDictionary, n.d. Web. 07 December 2018. <https://www.yourdictionary.com/master-gunnery-sergeant>.
master gunnery sergeant. (n.d.). Retrieved December 07th, 2018, from https://www.yourdictionary.com/master-gunnery-sergeant
(plural master gunnery sergeants)
(military, US) A non-commissioned officer of rank E-9 in the United States Marine Corps, ranking above a master sergeant/first sergeant and below a warrant officer. It is equal in grade to sergeant major