(UK, Navy) A warrant officer or chief petty officer responsible for discipline aboard a naval ship.

(Canada, Navy) A non-commissioned officer in the Canadian Forces Maritime Command, ranking above leading seaman and below petty officer second class.

plural of master seaman

(US, Navy) A non-commissioned officer in the United States Navy and United States Coast Guard, ranking above senior chief petty officer.

Alternative spelling of bargemaster

(law) Abbreviation of United States District Court for the District of Massachusetts, as used in case citations.

(astronomy) A unit of mass equal to the mass of the planet Jupiter, used to express the mass of other planets. 1 M_J = 2 × 10²⁷ kg.

(astronomy) A unit of mass equal to that of the Earth, used to express the mass of other planets etc. 1 M_🜨 = 6 × 10²⁴ kg.

plural of barge master

plural of mash note