Dishonorable
Part of speech: adjective
Definition: Without honor, or causing dishonor Lacking respect or ethical principles
Example sentence: After the situation with Kursk submarine, I started looking at Mr. Berezovsky in a completely different way. For me, it was a turning point in our relationship. I think that he took a completely dishonorable position.
Disreputable
Part of speech: adjective
Definition: not respectable, lacking repute; discreditable