- Mate
- Materia medica
- Material safety data sheet
- Maternal deprivation
- Maternal effect
- Maternal inheritance
- Maternal morbidity
- Maternal mortality
- Maternal near miss
- Maternal recognition of pregnancy
- Maternal to zygotic transition
- Maternal-fetal medicine
- Maternity hospital
- Maternity ward
- Mathematical expectation
- Mathematical model
- Mating type
- Mating-type locus
- Matricaria chamomilla
- Matricaria recutita
- Matricellular proteins
- Matrigel
- Matrilin
- Matrine
- Matriptase
- Matrix
- Matrix Gla protein
- Matrix gla protein
- Matrix metalloproteinase
- Matrix metalloproteinase inhibitor
- Matrix protein
- Matrix-M
- Maturation inhibitor
- Maturation promoting factor
- Mature minor doctrine
- Mature teratoma
- Maturity
- Maturity onset diabetes of the young
- Maturity-onset diabetes of the young
- Matuzumab
- Mavrilimumab
- Maxillary
- Maxillary antrum
- Maxillary artery
- Maxillary first molar
- Maxillary hypoplasia
- Maxillary nerve
- Maxillary prominence
- Maxillary second molar
- Maxillary second premolar
- Maxillary sinus
- Maxillary tuberosity
- Maxillary vein
- Maxillofacial surgery
- Maxillomandibular advancement
- Maximal inspiratory pressure
- Maximal oxygen uptake
- Maximization
- Maximum Residue Limit
- Maximum androgen blockade
- Maximum intercuspation
- Maximum life span
- Maximum parsimony
- Maximum permissible dose
- Maximum tolerated dose
- Maxon
- May-Hegglin anomaly
- Mayer waves
- Maytenus
- Mazindol
- Mazzotti reaction
- McArdle's disease
- McBurney's point
- McCarthy Scales of Children's Abilities
- McDonald criteria
- McFarland standards
- McGurk effect
- McKenzie Method
- McKusick-Kaufman syndrome
- McNemar test
- McRoberts maneuver
- Mdm2
- Me-too drug
- Meal replacement
- Mean airway pressure
- Mean arterial pressure
- Mean corpuscular hemoglobin
- Mean free path
- Mean residence time
- Meaning
- Meaning-making
- Measles
- Measles vaccine
- Measles virus
- Meat products
- Meat spoilage
- Meatal stenosis
- Meatotomy
- Meatus
- Mebendazole
- Mebeverine
- Mebrofenin
- Mecamylamine
- Mecasermin
- Mechanical ventilation
- Mechanism of action
- Mechanism of autism
- Mechanobiology
- Mechanochemistry
- Mechanomyogram
- Mechanoreceptors
- Mechanosensation
- Mechanosensitive ion channels
- Mechanostat
- Mechanotaxis
- Mechanotherapy
- Mechanotransduction
- Mecillinam
- Meckel syndrome
- Meckel's cartilage
- Meckel's cave
- Meckel's diverticulum
- Meckel-Gruber syndrome
- Meclizine
- Meclofenamic acid
- Meclofenoxate
- Meclozine
- Mecobalamin
- Meconium
- Meconium aspiration syndrome
- Meconium ileus
- Meconium peritonitis
- Mecoprop
- MedCalc
- MedWatch
- Medetomidine
- Media panic
- Medial
- Medial circumflex femoral artery
- Medial collateral ligament
- Medial condyle
- Medial cord
- Medial cutaneous nerve of arm
- Medial dorsal cutaneous nerve
- Medial dorsal nucleus
- Medial eminence
- Medial epicondyle
- Medial epicondyle of the femur
- Medial epicondyle of the humerus
- Medial epicondylitis