To rent, maybe, is not good (6)
I believe the answer is:
rotten
'is not good' is the definition.
I can't tell whether this definition defines the answer.
'to rent maybe' is the wordplay.
'maybe' indicates an anagram.
'to'+'rent'='torent'
'torent' is an anagram of 'ROTTEN'.
Can you help me to learn more?
(Other definitions for rotten that I've seen before include "Decayed or detestable" , "Something is ... in the state of Denmark (Hamlet)" , "Nasty" , "'Decayed, stinking (6)'" , "Suffering from decay" .)