MD

• Doctor of Medicine (Latin: Medicinae Doctor)
• Doctor of Medicine in Ayurveda
• MD (Homeopathy)

• Main droite or mano destra ('right hand'), in music terminology
• Music director
• MDs (TV series), a 2002 American medical drama
• Materiali e discussioni per l'analisi dei testi classici ('Materials and discussions for the analysis of classical texts'), an Italian journal
• MDTV (Indonesian TV network)

• Managing director, or chief executive officer, of an organization
• Madagascar Airlines, IATA airline code MD
• MD, aircraft model prefix of McDonnell Douglas
• MD Helicopters, American aerospace manufacturer
• MD Discount, Italian discount supermarket

• Moldova, ISO country code MD
• Maryland, United States, US postal abbreviation MD

Chemistry and physics

• Mendelevium, symbol Md, a chemical element
• Methyldichloroarsine, a chemical warfare agent
• Membrane distillation, a thermally driven separation process
• Millidarcy (mD), a unit of fluid permeability
• Molecular dynamics, a computer simulation method

Computing

• .md, Internet top-level domain for Moldova
• Markdown, a lightweight markup language, file extension .md
• MiniDisc, a discontinued erasable magneto-optical disc-based data storage format
• md, or mkdir, the "make directory" command
• Multiple device, as in Linux mdadm device driver

Medicine

• Ménière's disease, a disorder of the inner ear
• Muscular dystrophy, a group of diseases involving breakdown of skeletal muscles
• Muscle dysmorphia, a subtype of the body dysmorphic disorder

Other uses in science and technology

• Mean absolute difference, a measure of statistical dispersion
• Mesoscale discussion, in Storm Prediction Centers and Weather Prediction Centers
• Earthquake duration magnitude, M_d

• MD 20/20, a brand of fortified wine
• MD, 1500 in Roman numerals
• Majority decision, in full-contact combat sports
• 🅫 (marque déposée 'trademark', alternatively rendered ^MD), a Unicode compound superscript character
• Match Director in International Practical Shooting Confederation match
• Md, an alternative for Muhammad (name) or Mohammed