| MAINBOOM | • mainboom n. (Nautical) The boom (spar) of the mainsail. • MAINBOOM n. the spar that extends the foot of a fore-and-aft mainsail. |
| MAINDOOR | • MAINDOOR n. the principal door of an establishment. |
| MAINLAND | • mainland n. The continent; the principal land, as distinguished from islands or a peninsula. • mainland n. The principal island of a group. • Mainland prop.n. The largest island in the Orkney Islands council area, to the north of Scotland. |
| MAINLINE | • mainline adj. Normal, principal or standard. • mainline adj. (Rail transport) Of or pertaining to the principal route or line of a railway. • mainline adj. (Rail transport) Of or pertaining to a surface railway as distinct from an underground, elevated or light rail one. |
| MAINMAST | • mainmast n. (Nautical) The tallest mast of a sailing ship that has more than one mast; particularly a full-rigged ship. • main-mast n. Alternative spelling of mainmast. • MAINMAST n. the principal mast of a vessel. |
| MAINOURS | • mainours n. Plural of mainour. • MAINOUR n. (archaic) an act or fact of theft; that which is stolen, also MAINOR. |
| MAINSAIL | • mainsail n. (Nautical) The largest (or only) sail on a sailing vessel. • MAINSAIL n. the principal sail of a vessel. |
| MAINSTAY | • mainstay n. A chief support. • mainstay n. Someone or something that can be depended on to make a regular contribution. • mainstay n. (Nautical) A stabilising rope from the top of the mainmast to the bottom of the foremast. |
| MAINTAIN | • maintain v. (Obsolete, transitive) To support (someone), to back up or assist (someone) in an action. • maintain v. To keep up; to preserve; to uphold (A state, condition etc.). • maintain v. To declare or affirm (a clause) to be true; to assert. |
| MAINTOPS | • maintops n. Plural of maintop. • MAINTOP n. a platform at the head of a mainmast. |
| MAINYARD | • mainyard n. (Sailing) The yard of the mainmast, from which the mainsail is hung. • MAINYARD n. the lower yard on the mainmast. |