Disparage when weakened by illness (7)
I believe the answer is:
rundown
'disparage' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for rundown that I've seen before include "brief analysis" , "Disparage" , "Find fault" , "ski slope" , "Decry" .)