- M ... M45
- M47 ... Maazel, Lorin Varencove
- Mab ... MacArthur Fellows Program
- MacArthur Foundation ... MacDonald, John D.
- MacDonald, John Dann ... Macha
- Mácha, Karel Hynek ... Machuca, Pedro
- Machund River ... mackintosh
- Mackintosh, Charles Rennie ... Macpherson, James
- Macpherson, Jay ... Macrotis
- Macrotis lagotis ... Madame George
- Madame Jones ... Madhava
- Madhava I ... Madoff, Bernie
- Madog Ab Owain Gwynedd ... Madrigals and Motetts of 5 Parts
- Madrigals of War and Love ... Maffei 1 and 2
- Maffei 2 ... Maggiore, Lago
- Maggiore, Lake ... magistrates’ court
- Maglemosian industry ... magnetic pole
- magnetic prospecting ... magnitude-frequency analysis
- magnocellular layer ... Magsaysay, Ramon
- maguey ... Mahanadi River
- Mahānāleśvara ... Mahendravarman I
- Maher, Bill ... Mahra
- Mahra Sultanate ... Maillard reaction
- Maillart, Robert ... Mainz Convention
- Mainz, Berthold von ... Majesty, Letter of
- Maji Maji ... Majors, Alexander
- Majors, Jonathan ... Makhuwa language
- makhweyane ... Malabari
- Malabo ... Malatesta Family
- Malatesta Temple ... Malda
- Maldacena, Juan ... Mali i Sharrit
- Mali River ... Malkin, Evgeni
- Mälkki, Susanna ... Malone, Karl Anthony
- Malone, Kyp ... Malurus splendens
- Malus angustifolia ... Mamers
- Mamertini ... Man Died, The
- Man Escaped, A ... Man Who Sold the World, The
- Man Who Was Thursday, The ... Manala
- Manalo, Félix Ysagun ... Manchukoku
- Manchukuo ... Mandelstamm, Leonid Isaakovich
- Mander, Carel van ... Manfredi, Bartholomeo
- Manfredi, Doria ... Manguean languages
- Mangūjakid ... Manila, My Manila: A History for the Young
- Manilius, Gaius ... Mann, Carol
- Mann, Daniel ... Manon Lescaut
- Manon Lescaut ... Manṣūr, Muḥammad ibn Abū ʿĀmir al-
- Mansura, El- ... Manual Labor
- manual method ... Manych Trench
- Manyika ... Maplewell Series
- mapmaking ... Marāghah
- Marāgheh ... marbled murrelet
- marbled polecat ... March, Edmund Mortimer, 5th earl of, 3rd earl Of Ulster
- March, Edmund Mortimer, 5th Earl of, 3rd Earl of Ulster ... Marcus Aurelius Numerius Numerianus
- Marcus Aurelius Severus Alexander ... marennes
- Marenzio, Luca ... Margin account vs. cash account: What to know before you trade
- Margin Call ... Maria Island
- Maria Königin, Church of ... Marie-Antoinette-Josèphe-Jeanne d’Autriche-Lorraine
- Marie-Charlotte-Amélie-Augustine-Victoire-Clémentine-Léopoldine ... marine insurance
- marine ivy ... Marishi-ten
- Marismas, Hermandad de las ... Marked Woman
- markedness ... Marl
- Marlatt, Abby Lillian ... maroon community
- maroon oriole ... Marriage of Mr. Mississippi, The
- Marriage of Opposites, The ... Marseille Cathedral
- Marseille faience ... marshmallow
- marshmallow test, the ... Martialis, Marcus Valerius
- Martian Chronicles, The ... Martin, Quinn
- Martin, R. D. ... Marto, Jacinta
- Marton, Andrew ... Marxbrüder
- Marxism ... Marzobān I
- Marzouki, Moncef ... Mashal, Khaled
- Masham of Swinton, Samuel Cunliffe Lister, 1st Baron ... maso dance
- Maso degli Albizzi ... Mass Extinction
- mass extinction event ... Masses, The
- masseter ... master positive
- Master Sun’s Mathematical Manual ... Mat
- Mat ... material
- material balance ... Matheran
- Mathers, Marshall Bruce, III ... Matmata
- Maṭmāṭah ... Matsuwaka-Maru
- Matsuyama ... Matthias I
- Matthias, St. ... Mauer
- Mauer jaw ... Mauritia flexuosa
- Mauritian Creole ... Maxam, Allan M.
- Maxam-Gilbert method ... Maxwell, James Clerk
- Maxwell, Jody-Anne ... Maydān-e Shah
- Mayday ... Mayor Daley Marathon
- Mayor of Casterbridge, The ... Mazeroski, Bill
- Mazhilis ... MBNA
- MBO ... McCarran, Patrick A.
- McCarrick, Theodore ... McCormick, Patricia Joan
- McCormick, Peter Dodds ... McDougall, William
- McDowall, Alastair ... McGuire, Alfred James
- McGuire, Barry ... McLaglen, Victor
- McLain, Denny ... McNally, Terrence
- McNamara, Robert S. ... Me and Bobby McGee
- Me and My Gal ... Meaning of Contemporary Realism, The
- Meaning of Evolution, The ... mechanical doping
- mechanical drawboy ... MECP2
- Mecsek Mountains ... medical benefit
- medical cannabis ... medicine
- medicine ... Mediterranean low
- Mediterranean macchia ... Meeker, Nathan Cook
- Meenakshi Amman Temple ... Megalodontoidea
- Megalokastro ... Mehābād
- Meharry Medical College ... Meiji Shrine
- Meiji Tennō ... Mekele
- mekhirat ḥametz ... Melayu music
- mĕlayu pasar language ... Melishipak
- melisma ... meloponine bee
- Melopsittacus undulatus ... memetics
- memex ... Memorial University of Newfoundland
- Memoriale ... Men’s Club, The
- Men, The ... Mendès-France, Pierre
- Méndez de Haro, Don Luis ... Mengü Temür
- Mengxi bitan ... Mensa Bonsu
- Mensa International ... Menzel, Adolf von
- Menzel, Idina ... mercerization
- Mercersburg Review ... Mercury Rising
- mercury salt ... Meriden
- meridian ... meroblastic cleavage
- Merodach-Baladan II ... Merseburg
- Merseburg Charms ... Meschke, Michael
- Mesechinus ... mesophase
- mesophile ... Messenia
- Messenia, Gulf of ... Metabolist school
- metabolite ... metamathematics
- metamatic ... Metaxya lanosa
- Metaxya rostrata ... Methanosarcina
- Methanothermobacter thermautotrophicus ... methylene green
- methylene group ... Metropolitan Opera House
- Metropolitan Police ... Mexican fruit bat
- Mexican fruit fly ... Meyer, Kurt
- Meyer, Leonard ... MHD duct
- MHD generator ... Michael
- Michael ... Michels, Marinus Hendrikus Jacobus
- Michels, Rinus ... microbead
- Microbead-Free Waters Act ... Microhierax
- microhistory ... microsome
- microsound ... Midas City
- Midas Monument ... Middle Stone Age
- middle story ... Midlands
- midlatitude cell ... Mien-yang
- Mienic languages ... migratory phase
- Migratory Species of Wild Animals, Convention on the Conservation of ... mikveh
- Mil Mi-12 ... Milesians
- Milestone, Lewis ... Military Service Act
- Military Service Law ... millefleur tapestry
- Millen, Matt ... Miller, Max
- Miller, May ... Millonarios
- millones ... Miltown
- Milutin ... Min River
- Min Shan ... mind-stuff
- Mind: An Essay on Human Feeling ... Mines, Chamber of
- Mines, College of ... minim
- Minim Brothers, Order of ... Minnekahta
- Minnelli, Lester Anthony ... Minos, Palace of
- Miñoso Armas, Saturnino Orestes Arrieta ... Miopithecus talapoin
- MIP ... Miraj
- Miraj ... Mirror of Criticism, The
- Mirror of Kings ... Misgivings
- Misgurnus ... Miss Sharon Jones!
- Miss Sloane ... Missions in Africa and the East, Society for
- missions, Spanish ... Mistick Fort, Battle of
- Mistinguett ... Mitchella repens
- Mitchum, Robert ... Mitsotakis, Kyriakos
- mitsu-gusoku ... mixed-grass prairie
- mixed-layer inversion ... MKK system
- mks set ... Mo seung
- MO theory ... Moçambique
- Moçambique, Banco de ... model building
- model checking software ... Modern Pueblo period
- modern Republicanism ... Modularity of Mind
- modulation ... Mogul dynasty
- Mogul glass ... Moi, Tituba, sorcière—: noire de Salem
- moidam ... molarity
- molas ... molecular sieve
- molecular solid ... Molotov cocktail
- Molotov, Vyacheslav ... Mona
- Mona ... Mond carbonyl process
- Mond Laboratory ... Monge’s disease
- Monge, Gaspard, comte de Péluse ... Monk, George, 1st duke of Albemarle, earl of Torrington, Baron Monck of Potheridge, Beauchamp and Teyes
- Monk, James Arthur ... Monocirrhus polyacanthus
- Monoclea ... monopolistic competition
- Monopoly ... Monsieur Bergeret in Paris
- Monsieur Hulot ... Montagu, 1st marquess of
- Montagu, Ashley ... Monte-Carlo, Casino de
- Montebello Islands ... Montfort-l’Amaury
- Montforts, The ... Montreal Alouettes
- Montreal Amateur Athletic Association ... Moody, Paul
- Moody, Rick ... Moonrise
- Moonrise Kingdom ... Moore, Stanford
- Moore, Thomas ... moral relativism
- moral responsibility, problem of ... Morbus Kitahara
- Morceli, Noureddine ... morepork
- Morera, Enrique ... Morgantown
- Morganucodon ... Morley, Thomas
- Morley-Minto Reforms ... Morotai
- Moroto ... Morris, Stephen
- Morris, Stevland Hardaway ... Mortality
- mortality ... Morven
- Morvi ... Moseley, Carol
- Moseley, Henry ... Mosquito Coast, The
- Mosquito Coast, The ... moth
- Moth ... Motilón
- motion ... motor-voter law
- motorbike ... moulting
- Moulton, Alex ... Mount Vernon
- Mount Wilson Catalog of Photographic Magnitudes in Selected Areas ... Mountains and Sea
- Mountains of the Moon ... mouthbreeder
- mouthparts ... Movimiento de la Quinta República
- Movimiento de Liberación Nacional ... Mozarabic art
- Mozarabic chant ... Mr. and Mrs. ’55
- Mr. and Mrs. Andrews ... Mrożek, Sławomir
- MRP ... MTS1
- Mtshali, Oswald Mbuyiseni ... mucus
- mucus tract ... Mufu Mountains
- Mufu Shan ... Muḥammad ibn Sālim
- Muḥammad ibn Salmān ibn ʿAbd al-ʿAzīz Āl Saʿūd ... muḥtasib
- Muhteşem ... Mulatto
- mulatto ... Müller, Johannes von
- Müller, K. Alex ... multilateral treaty
- multilateralism ... multitrack recorder
- Multituberculata ... Munchkinland
- munchkins ... municipio
- municipium ... Muppet Magazine
- Muppet Movie, The ... Murchison Falls National Park
- Murchison meteorite ... Murillo, Gerardo
- Murillo, Rosario ... Murray, Arthur
- Murray, Balvany, and Gask, John Murray, Lord ... Murwillumbah
- Muryangsu Hall ... Muscle of Love
- muscle of Riolan ... museum of modern art
- Museum of New Zealand Te Papa Tongarewa ... Music of the Spheres
- Music Performance Trust Fund ... musk okra
- musk ox ... Mustaine, Dave
- Mustakfī, al- ... Muthuswami Dikshitar
- Muti, Riccardo ... Muzsika
- Muztag, Mount ... My Childhood
- My company 401(k) plan offers a Roth option. Should I use it? ... My Name Is Julia Ross
- My Name Is Khan ... Mycobacterium avium-intracellulare
- Mycobacterium bovis ... Mylar
- Myliobatidae ... Myrdal, Karl Gunnar
- Mýrdals Glacier ... Mysteries of Paris, The
- Mysteries of Pittsburgh, The ... myxamoeba
- myxedema ... Mʾzabite
