Deteriorates (4)
'deteriorates' is the definition.
(rotting is a kind of deteriorating)
This is the entire clue.
(Other definitions for rots that I've seen before include "Decomposes" , "Decays" .)
'deteriorates' is the definition.
(I've seen this in another clue)
This is all the clue.
(Another definition for worsens that I've seen is " Deteriorates in New Ross".)