WordNet (r) 3.0 (2006):

mayidism
    n 1: a disease caused by deficiency of niacin or tryptophan (or
         by a defect in the metabolic conversion of tryptophan to
         niacin); characterized by gastrointestinal disturbances and
         erythema and nervous or mental disorders; may be caused by
         malnutrition or alcoholism or other nutritional impairments
         [syn: pellagra, Alpine scurvy, mal de la rosa, mal
         rosso, maidism, mayidism, Saint Ignatius' itch]