Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.

For example, the constellation of numbness of the neck, arms, and back with headache, dizziness, profuse sweating, and palpitations after eating Chinese food laden with monosodium glutamate (MSG) strongly suggests the Chinese restaurant syndrome. Other examples include the acquired immunodeficiency syndrome (AIDS), the achoo syndrome, the alien hand syndrome, the sick building syndrome, the stiff baby syndrome, and many, many more.

The word "syndrome" has long been popular in medicine and, more recently, outside medicine (as in the "China syndrome"). The word comes from the Greek "syn-" meaning together + "dramein" meaning to run = to run together, or go together.