- Macacus... to Macrogyria...
- Macrohydrocephalus... to Majocchi...
- Major... to Malherbe...
- Malibu... to Mammillitis...
- Mammitis... to March...
- Marchand... to Marshall...
- Martin... to Masturbation...
- Maternal... to Meconium...
- Median... to Megalencephaly...
- Megalerythema... to Meige...
- Melalgia... to Melioidosis...
- Melitensis... to Meninges...
- Meningioma... to Menkes...
- Menolipsis... to Merycism...
- Merzbacher... to Metamorphopsia...
- Metaplasia... to Mice...
- Micheli... to Microglioma...
- Microglossia... to Midplane...
- Miescher... to Miller...
- Milles... to Missed...
- Missing... to Molimen...
- Mollaret... to Mononeuritis...
- Mononeuropathy... to Morning...
- Moron... to Mounier...
- Mountain... to Mucoviscidosis...
- Mucus... to Mushrooming...
- Mutation... to Myelocytic...
- Myelocytoma... to Myelosarcoma...
- Myelosclerosis... to Myofibrositis...
- Myopathy... to Myxosarcoma...