• Anger
• Madness, the state of being irrational or suffering from mental illness
• Mad (magazine), an American humor magazine and its various spinoffs:
• MADtv, a sketch comedy television series
• Mad Magazine Card Game
• The Mad Magazine Game
• Mad River, various rivers
• Mad (village), a village in the Dunajská Streda District of Slovakia
• Mad (band), a rock band from Buenos Aires, Argentina

MAD may be an acronym for:

• Mutual assured destruction, a doctrine of military strategy
• Madrid Barajas International Airport, the IATA airport code
• MAD TV (Greece), a Greek music channel
• MAD (poem), a poem by the World War I poet Wilfrid Wilson Gibson
• MAD Studio, an architectural firm
• MAD Movie, a Japanese fan-made video, much like an Anime Music Video. MAD can also describe the Japanese AMV community
• MAD programming language (short for Michigan Algorithm Decoder)
• MAD Multiply and Add in computer science, a low level instruction for the GPU
• Magnetic airborne detector
• Magnetic anomaly detector, a scientific instrument and anti-submarine warfare detection device
• Malevolent Agency of Destruction, a fictional evil organization led by Dr. Claw from the cartoon series Inspector Gadget
• Mandibular advancement device, an appliance worn in the mouth to treat obstructive sleep apnea or snoring
• Maximal areal density
• Mean absolute deviation, a statistical measure of variability
• Median absolute deviation, a statistical measure of variability, more resistant to outliers
• Mean absolute distance, a mathematical function
• Meg and Dia, American indie rock band
• Methodical Accelerator Design, Particle accelerator simulation tool
• Militärischer Abschirmdienst, the Military Counterintelligence division of the German Army
• Moroccan dirham, the ISO 4217 code for the currency of Morocco
• MPEG Audio Decoder, an audio decompression software
• Multi-wavelength anomalous dispersion, a technique used in X-ray crystallography
• Multiple Access Dialer, a dialer developed by Compuspec that can access a variety of telecom networks in case one service is not available
• Museum of Arts & Design, located in New York City