One of the bits of leather or coloured bunting placed upon a sounding line at intervals of from two to five fathoms. (The unmarked fathoms are called "deeps".)

A commodity, usually produced on farms and part of a larger category. Products within a market class have similar physical characteristics, are grown or raised under similar conditions, and are bought and sold under similar terms and conditions.

maroon

nounMarine and shipyard

A rocket-propelled firework or skyrocket, often one used as a signal (for example, to summon the crew of a lifeboat or warn of an air raid).

MARPOL

nameMarine and shipyard

The International Convention for the Prevention of Pollution from Ships.

MARPOL 73/78

nameMarine and shipyard

The International Convention for the Prevention of Pollution from Ships.

marquetry

nounWoodworking

A decorative technique in which veneers of wood, ivory, metal etc. are inlaid into a wooden surface to form intricate designs.

marrow

nounMining and extractionobsolete, slang

A miner's mate or assistant.

Mars rover

nounAviation maintenance

A vehicle, either crewed or uncrewed, designed to travel across the surface of Mars for scientific exploration.

marshalling

nounRail equipment

The sorting of rolling stock in a marshalling yard.

martensite

nounMetallurgy

A solid solution of carbon in iron; the chief constituent of steel.

Martindale

nounTextile production

A unit for quantifying the abrasion resistance of textiles, especially when used for upholstery.

Martindale method

nounTextile production

A test designed to measure the durability of a fabric.

marver

nounGlass and ceramics

A flat heatproof surface on which a gather of glass is rolled into shape.

mash

nounManufacturing

Ground or bruised malt, or meal of rye, wheat, corn, or other grain (or a mixture of malt and meal) steeped and stirred in hot water for making the wort.

mash tun

nounManufacturing

An insulated vessel used in making the mashing process in which grains and water are mixed and heated to produce wort prior to fermentation.

masher

nounManufacturing

A machine for making mash.

mashout

nounManufacturing

The step or process, in brewing beer, of raising the mash (e.g. by adding hot water to it) to a temperature around 75 °C or 170 °F, so as to stop the enzymatic conversion of starch to fermentable sugar and make the mash and wort more fluid.

mashwort

nounManufacturing

wort that is not separated from the grains

mask work

nounIndustrial electronics

A type of three-dimensional image or pattern on a layer of materials used to design or manufacture a semiconductor chip.

mass distribution

nounMechanical engineering

The spatial distribution of mass within a solid body.

mass haul diagram

nounIndustrial supplies, equipment, and components

A diagram illustrating the amounts of material that will be cut from the terrain and used to fill other areas, for example when building a railway.

mass storage

nounIndustrial electronics

Any form of data storage (non-volatile memory) with high capacity relative to that of the faster volatile memory of computers (of its time).

mast

verbForestry and timber

To produce a very large quantity of fruit or seed in certain years but not others.

MastCam

nounAviation maintenance

Abbreviation of Mast camera, a type of camera found on certain unmanned space rovers including the Curiosity rover at Mars.

master copy

nounIndustrial printing

The copy that acts as the main or original version among several copies, such as the master proof where changes from other author copies are combined, or a similar master manuscript with edits transferred to it.

match

nounMetalworking

A perforated board, block of plaster, hardened sand, etc., in which a pattern is partly embedded when a mould is made, for giving shape to the surfaces of separation between the parts of the mould.