phthi·sis 
(thīsĭs, tī-, thĭsĭs, tĭs-)
(thīsĭs, tī-, thĭsĭs, tĭs-)n.
1. A disease characterized by the wasting away or atrophy of the body or a part of the body.
2. Tuberculosis of the lungs. No longer in scientific use.
[Latin, from Greek, from phthinein, to waste away.]