WordNet (r) 3.0 (2006):

cystic fibrosis
    n 1: the most common congenital disease; the child's lungs and
         intestines and pancreas become clogged with thick mucus;
         caused by defect in a single gene; no cure is known [syn:
         cystic fibrosis, CF, fibrocystic disease of the
         pancreas, pancreatic fibrosis, mucoviscidosis]