- master batch
- maneb
- manganese carbonate
- manganese garnet
- manganese pig
- manganophylite
- manganuos
- Manila paper
- mannitol
- mannose
- manual work
- manufactured
- map scale
- maraging steel
- marcasite
- marginal deep
- marginal deposit
- marginal moraine
- marignacite
- marine facies
- marine oil
- marine riser
- marine sediment
- marjoram oil
- markefieldite
- marketable oil
- marketable ore
- marl
- material flaw
- material well
- materials characteristic
- materials flaw
- materials stiffness
- matildite
- matrix fuel
- maturation
- mature valley
- maturity
- maximum capacity
- maximum output
- maximum tress
- maximum valence
- maximum weight
- mazout
- meadow ore
- mealy limestone
- mean depth
- mean efficiency
- mean molecule
- mean range
- meander survey
- measures
- marlpit
- marly clay
- marmatite
- maroon
- marshite
- Martens test
- martensite
- martinite
- martonite
- mass formula
- mass movement
- mass velocity
- massive structure
- master cylinder
- master form
- master gear
- master plant
- master tap
- mastic
- mastic asphalt
- mastic block
- mastic oil
- masticate
- mastication
- match
- matched terrace
- material balance
- mechanical dewaxing
- mechanical digger
- mechanical draft
- mechanical engineering
- mechanical impurities
- mechanical injection
- mechanical instability
- mechanical life
- mechanical loader
- mechanical loading
- mechanical polishing
- mechanical preparation
- mechanical press
- mechanical test
- mechanical undercutter
- mechanical weathering
- medial moraine
- medicinal wax
- Mediterranean suite
- medium oil
- medium pitch