DEGENERATIVE
Meaning of DEGENERATIVE in English
de ‧ gen ‧ e ‧ ra ‧ tive /dɪˈdʒen ə rətɪv/ BrE AmE adjective
a degenerative illness gradually gets worse and cannot be stopped ⇨ progressive
Longman Dictionary of Contemporary English.
Longman - Словарь современного английского языка.
2012