1) Characterized by degeneration 2) Chronic 3) Of illness 4) Tending to degenerate 1) Chronic 
• (a.) Undergoing or producing degeneration; tending to degenerate.
undergoing degeneration : tending to degenerate; having the character of or involving degeneration; causing or tending to cause degeneration.
<pathology> Undergoing degeneration: tending to degenerate, having the character of or involving degeneration, causing or tending to cause degeneration. ... (18 Nov 1997) ... 
De·gen'er·a·tive adjective Undergoing or producing degeneration; tending to degenerate. 
Type: Term Pronunciation: dĕ′jen′ĕr-ă-tiv Definitions: 1. Relating to degeneration.
[adj] - of illness
adjective (of illness) marked by gradual deterioration of organs and cells along with loss of function; `degenerative diseases of old age`
tending to degenerate. · characterized by degeneration.