degenerative
/dɪˈdʒenərətɪv/adjective
1- (of a disease or symptom) characterized by progressive (often irreversible) deterioration and loss of function in the organs or tissues（疾病, 症状）不断恶化的：
degenerative diseases.
变性疾病。
1.1
- of or tending to decline and deterioration退化的; 变坏的：
the young generation had fallen into a degenerative backslide.
年轻的一代已经堕落倒退了。