- Morningness-Eveningness Questionnaire
- Moro reflex
- Moronic acid
- Morphiceptin
- Morphinan
- Morphine
- Morphine addiction
- Morphine-6-glucuronide
- Morphogenesis
- Morpholine
- Morpholino
- Morphology
- Morphometrics
- Morphometry
- Morquio syndrome
- Morris water maze test
- Morse Fall Scale
- Mortality
- Mortality rate
- Mortality salience
- Morton's neuroma
- Morton's toe
- Morula
- Morus
- Morus alba
- Morvan's syndrome
- Mosaicism
- Mosapride
- Mosquito bite
- Mosquito bite allergy
- Mosquito control
- Mosquito nets
- Mosquito-borne diseases
- Mossy fibers
- Most probable number
- Most recent common ancestor
- Mothballs
- Mother-to-child transmission
- Motherhood
- Motile cilia
- Motilin
- Motilin receptor
- Motion parallax
- Motion perception
- Motion sickness
- Motivated behavior
- Motivated forgetting
- Motivated reasoning
- Motivation
- Motivational enhancement therapy
- Motivational interviewing
- Motivational therapy
- Motoneuron
- Motor adaptation
- Motor cognition
- Motor control
- Motor coordination
- Motor cortex
- Motor development
- Motor disorders
- Motor dysfunction
- Motor end plate
- Motor imagery
- Motor learning
- Motor nerve
- Motor neuron
- Motor neuron disease
- Motor neuron diseases
- Motor neurone disease
- Motor neurons
- Motor neuropathy
- Motor program
- Motor proteins
- Motor speech disorders
- Motor system
- Motor unit
- Motor unit recruitment
- Mottle
- Moulage
- Mould growth
- Mouse ear swelling test
- Mouse mammary tumor virus
- Mousepox
- Mouth
- Mouth breathing
- Mouth cancer
- Mouth ulcers
- Mouthfeel
- Mouthing
- Mouthparts
- Mouthwash
- Movement assessment
- Mowat-Wilson syndrome
- Moxetumomab pasudotox
- Moxibustion
- Moxidectin
- Moxifloxacin
- Moxonidine
- Moyamoya disease
- Mozart effect
- Mu rhythm
- Mucicarmine stain
- Mucilage
- Mucin
- Mucin-1
- Mucinosis
- Mucinous adenocarcinoma
- Mucinous carcinoma
- Mucinous carcinoma of the breast
- Mucinous cystadenoma
- Mucinous cystic neoplasm
- Mucins
- Muckle-Wells syndrome
- Mucoadhesion
- Mucocele
- Mucociliary clearance
- Mucocutaneous junction
- Mucoepidermoid carcinoma
- Mucogingival junction
- Mucolipidoses
- Mucolipidosis
- Mucolipidosis type IV
- Mucolytic agent
- Muconic acid
- Mucoperiosteum
- Mucopolysaccharidosis
- Mucopolysaccharidosis type I
- Mucoprotective
- Mucoprotein
- Mucopurulent discharge
- Mucor
- Mucormycosis
- Mucosa
- Mucosa-associated lymphoid tissue
- Mucosal immunity
- Mucosal immunology
- Mucosal melanoma
- Mucosal surfaces
- Mucosal tissue
- Mucosal-associated invariant T cells
- Mucosectomy
- Mucositis
- Mucous cell
- Mucous glands
- Mucous membrane
- Mucous membrane pemphigoid
- Mucuna
- Mucuna pruriens
- Mucunain
- Mucus