Contumelious is a related term of discreditable.
As adjectives the difference between contumelious and discreditable
is that contumelious
is (archaic|literary) rudely contemptuous; showing contumely; insolent or disdainful while discreditable
is able to be discredited.
(archaic, literary) Rudely contemptuous; showing contumely; insolent or disdainful.
* 1879 ,
- The pad would not stay on Modestine’s back for half a moment. I returned it to its maker, with whom I had so contumelious a passage that the street outside was crowded from wall to wall with gossips looking on and listening.
* (rudely contemptuous) disdainful, insolent
Able to be discredited.
Low, mean, bringing discredit.