| Term No. | Term Name | Term Description |
| 3709 | Marseilles canal type outlet | A module used on the Marseilles canal in France. It is housed in a small locked room. At the bottom of a masonry system connected with the canal there..... |
| 2078 | Marsh | An area of soft, wet or periodically inundated land, generally treeless and usually characterized by grasses and other low growth...... |
| 6763 | Marsh | 1 ‑ Area of low‑lying wetland, usually characterized by non‑woody vegetation; may be either fresh or salt water. 2 ‑ See 2078...... |
| 6766 | Marshlands | Areas interspersed with open water, emergent vegetation (hydrophytes) and terrestrial vegetation (phreatophytes)...... |
| 5543 | Masonry cement | Cement used for masonry having higher values of setting time...... |
| 2330 | Masonry dam | A dam composed of one or more of the following materials : bricks or stone masonry or concrete (plain, reinforced, prestressed)...... |
| 3248 | Masonry lining, Brick lining, Tile lining, Block lining, or Stone lining | A type of canal lining involving the use of bricks, tiles, concrete blocks and stones...... |
| 3758 | Masonry syphon | A syphon, the barrel/barrels of which is/are built of masonry (bricks or plain concrete)...... |
| 2331 | Masonry-cum-earth dam | A dam comprising a portion made of earth and a part in masonry along its length (length of spillway portion being excluded)...... |
| 406 | Mass | img:equations//403_406_e.jpg..... |
| 408 | Mass | img:equations//407_408_e.jpg..... |
| 422 | Mass | img:equations//422_426_e.jpg..... |
| 546 | Mass | img:equations//546_e.jpg..... |
| 444 | Mass activity, Specific activity | img:equations//..... |
| 5570 | Mass concrete | Concrete produced with relatively small amount of mortar to lower down the heat generated and the rise in temperature, and/or to reduce the shrinkage,..... |
| 925 | Mass curve, Mass diagram, Summation graph, Summation curve | 1 – A graph in which values of cumulative rainfall or runoff are plotted against time. 2 – See 79...... |
| 442 | Mass defect | img:equations//442_445_e.jpg..... |
| 79 | Mass diagram, Mass curve, Flow integrated curve, or Summation curve | A diagram, curve, or graph, plotted with rectangular coordinates, representing a summation (integration) of all preceding quantities up to a point. Ea..... |
| 807 | Mass rainfall curve, or Mass precipitation curve | A plot of accumulated precipitation against time...... |
| 1670 | Massive | A large mass of soil manifesting irregular shape and cleavage...... |
| 6132 | Mast frame | A frame that allows a tower or vertical beam carries one or more load lines at its top...... |
| 8211 | Master file | A file or relatively more permanent information, that is usually updated periodically...... |
| 1621 | Master horizons | Under this title are listed the principal soil horizons and layers in soil profiles: H, O, A, E, and B, and the underlying C and R...... |
| 6186 | Master station | A station that may receive telemetered data and from which remotely located equipment is controlled...... |
| 5800 | Mastic asphalt | A mix of fine mineral aggregate, filler and bitumen, with or without chippings, all in such proportions that the mix can be applied hot by pouring or ..... |
