Speak disparagingly to derelict (3-4)
I believe the answer is:
run down
'derelict' is the definition.
(I know that derelict can be written as run-down)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for run down that I've seen before include "exhaust?" , "slightly off" , "brief summary" , "Drained" , "After search" .)