M&A (Mergers and Acquisitions)
MAC (Main Automation Contractor)
Macro Policy (or Macroeconomic Policy)
Macrocell/ Macrocell Corrosion
Magnetic Resonance Imaging (MRI)
Magnetic Resonance Spectroscopy (MRS)
Make up Accounting (or Cosmetic Accounting or Accounting Scandal)
Malware (or Malicious Software)
Management information System (MIS)
Manual J (Heating and Cooling Load Calculations)
Manufacturing Engineering Laboratory (MEL)
Markit PMI (Purchasing Manager’s Index)
Master Schedule (Level 1 Schedule)
Matrix Organisation (or Hybrid Organisation)
Maximum Allowable Concentration (MAC)
Maximum Allowable Operating Pressure (MAOP)
Maximum Allowable Working Pressure (MAWP)
Maximum Contaminant Level (MCL)
Maximum Explosion Pressure, Pmax
Maximum Permissible Concentration (MPC)
Maximum Power Point Tracker (MPPT)
MCC (Motor Control Centre) and iMCC (Intelligent or Integrated MCC)
MDI (Methylene Diphenyl Diisocyanate)
Mean Power Output (of a Wind Turbine)
Mean Time Between Failure (MTBF)
MEC (Main Electrical Contractor)
Mechanical Completion Certificate (MCC)
Mechanical Datasheet (Data Sheet)
Medium-Density Fibreboard (MDF)
MERS (Middle East Respiratory Syndrome)
Micro-Electromechanical Systems (MEMS)
Microorganism (Micro-organism or Microbe)
Microwave Nondestructive Testing (MNDT)
Middle Distillate Synthesis (MDS)
Mineral Acid (or Inorganic Acid)
Minimisation of Natural Hazard
MMAS (Material Management and Accounting System)
Mobile Fire Fighting Equipment Schedule
Modularisation (Modularization)
Molar Enthalpy of Vaporisation
Molten Carbonate Fuel Cell (MCFC)
Monocrystalline Silicon Solar Cell (mono-Si)
Monte Carlo Method for Autocorrection
Monte Carlo Technique (Monte Carlo Analysis or Monte Carlo Method)
Mortgage-Backed Security (MBS)
MOU (Memorandum of Understanding)
MSD (Material Selection Diagram)
MSDS (Material Safety Data Sheet)
MT (Magnetic Particle Testing)
MTBE (Methyl tertiary butyl ether)
MTI (Medical Treatment Injuries)
MTO (Material Take-Off) Allowance
Municipal Waste to Energy Project (or Plant)