fibrosis /fībrō″sis/ [L, fibra + Gk, osis, condition] , 1. a proliferation of fibrous connective tissue that occurs normally in the formation of scar tissue to replace tissue lost through injury or infection. 2. an abnormal condition in which fibrous connective tissue spreads over or replaces normal smooth muscle or other normal organ tissue. Fibrosis is most common in the heart, lung, peritoneum, and kidney. See also cystic fibrosis, fibromyalgia.
