- Maleic anhydride
- Maleimide
- Malfunctions
- Malic acid
- Malignancy
- Malignant
- Malignant hyperthermia
- Mall intercept
- Malleability
- Malleable iron
- Malleolus
- Malleus
- Malliavin calculus
- Malloc
- Malnutrition
- Malondialdehyde
- Malonic acid
- Maltase
- Maltenes
- Maltitol
- Maltodextrin
- Maltose
- Maltotriose
- Malunion
- Malware
- Malware analysis
- Mammary gland
- Mammography
- Mammoplasty
- Mammotome
- Man-computer symbiosis
- Man-in-the-middle attacks
- Managed lanes
- Managed security service
- Managed services
- Management cybernetics
- Management fads
- Management plane
- Management science
- Mancozeb
- Mandelbrot set
- Mandelic acid
- Mandelonitrile
- Mandible
- Mandibular symphysis
- Mandrels
- Manganate
- Manganese
- Manganese carbonate
- Manganese chloride
- Manganese deficiency
- Manganese dioxide
- Manganese hydroxide
- Manganese nodules
- Manganese oxide
- Manganese peroxidase
- Manganese phosphate
- Manganese steel
- Manganese sulfate
- Manganese(ii) chloride
- Manganese-56
- Manganin
- Manganism
- Manganite
- Manganosite
- Mangiferin
- Mangroves
- Manhattan distance
- Manhattan plot
- Manifest file
- Manifold vacuum
- Manifolds
- Manipulability ellipsoid
- Manipulators
- Mann-Whitney U
- Mannan
- Mannans
- Mannich bases
- Mannich reaction
- Manning formula
- Mannitol
- Mannitol Salt Agar
- Mannose
- Mannose receptor
- Mannuronic acid
- Manometer
- Mantel test
- Mantle
- Mantle convection
- Mantle plumes
- Mantle wedge
- Manual override
- Manual therapy
- Manual transmission
- Manufacturing
- Manufacturing cost
- Manufacturing engineering
- Manufacturing operations
- Manufacturing process management
- Manure
- Manure management
- Manus
- Manuscripts
- Many-to-many
- Many-valued logic
- Manycore
- Map
- Map algebra
- Map graph
- Map projections
- MapReduce
- MapServer
- Mapbox
- Maple
- Maplesim
- Mapping
- Maraging steel
- Marangoni effect
- Marble
- Marcasite
- Marching cubes
- Marching squares
- Marcus theory
- Margaric acid
- Margin
- Margin classifier
- Margin of error
- Marginal
- Marginal abatement cost
- Marginal distribution
- Marginal land
- Marginal likelihood
- Marginal stability
- Marginal utility
- Marginal zone
- Marginally stable
- Mariana Trench
- Marinas
- Marine
- Marine bacterium
- Marine chronometers
- Marine clay
- Marine debris
- Marine diesel oil
- Marine ecosystem
- Marine electronics
- Marine energy
- Marine engineering
- Marine heatwaves
- Marine microorganisms