Surface damage caused by bad rust? (4)
I believe the answer is:
ruts
'surface damage caused' is the definition.
I can't tell whether this definition defines the answer.
'bad rust?' is the wordplay.
'bad' indicates an anagram.
'rust' with letters rearranged gives 'RUTS'.
'by' is the link.
Can you help me to learn more?
(Other definitions for ruts that I've seen before include "Ditches" , "Deep tracks in paths" , "Deep furrows" , "Furrows not to get stuck in" , "gets ready for new partner" .)