China 
Africa 
- Melioidosis
- Melittin
- Mellin Transform
- Mellitic acid
- Meloidogyne incognita
- Melon
- Melphalan
- Melt
- Melt blowing
- Melt inclusions
- Melt ponds
- Melt spinning
- Meltdown
- Melting
- Melting curve analysis
- Melting point
- Melting-point depression
- Meltwater
- Membership function
- Membrane bioreactor
- Membrane channels
- Membrane computing
- Membrane curvature
- Membrane filtration
- Membrane fluidity
- Membrane fouling
- Membrane fusion
- Membrane gas separation
- Membrane lipids
- Membrane models
- Membrane oxygenator
- Membrane potential
- Membrane proteins
- Membrane reactors
- Membrane scaling
- Membrane structures
- Membrane technology
- Membrane theory of shells
- Membrane transport
- Membrane transport proteins
- Membranes
- Membranous labyrinth
- Membranous nephropathy
- Memcached
- Memetic algorithms
- Memex
- Memoization
- Memorandums
- Memory
- Memory B cells
- Memory T cells
- Memory access pattern
- Memory address
- Memory bandwidth
- Memory bank
- Memory cell
- Memory controller
- Memory density
- Memory effect
- Memory foam
- Memory footprint
- Memory hierarchy
- Memory management
- Memory model
- Memory module
- Memory pools
- Memory protection
- Memory span
- Memoryless
- Memorylessness
- Memristors
- Menadione
- Menarche
- Mendelian inheritance
- Mengovirus
- Meninges
- Meningioma
- Meningitis
- Meniscus
- Menopause
- Menstrual cycle
- Menstruation
- Mental models
- Mental ray
- Mental status examination
- Menthofuran
- Menthol
- Menthone
- Menu
- Mercaptobenzothiazole
- Mercaptopurine
- Mercapturic acid
- Mercer's theorem
- Mercerisation
- Merchant marine
- Merchant ships
- Merck Molecular Force Field
- Mercuric oxide
- Mercury
- Mercury and air toxics standards
- Mercury cadmium telluride
- Mercury chloride
- Mercury cycle
- Mercury glass
- Mercury methylation
- Mercury oxide
- Mercury poisoning
- Mercury reductase
- Mercury selenide
- Mercury telluride
- Mercury thermometers
- Mercury(ii) nitrate
- Mercury(ii) sulfate
- Mercury-vapor lamps
- Mereology
- Mereotopology
- Merge
- Merge sort
- Meridian
- Merit order
- Merkel cell
- Merkel cell carcinoma
- Merkel-cell carcinoma
- Meromorphic functions
- Merox
- Merozoite surface protein
- Merrifield resin
- Merrill-Crowe process
- Mersenne primes
- Mesangial cells
- Mesas
- Mesenchyme
- Mesenteric arteries
- Mesenteric ischemia
- Mesentery
- Mesh
- Mesh generation
- Mesh networks
- Mesh parameterization
- Meshfree methods
- Mesitylene
- Mesna
- Mesocosms
- Mesoderm
- Mesogens
- Mesoionic
- Mesolite
- Mesomeric effect
- Mesophase
- Mesophiles