The word "ignoble" means dishonorable or despicable. In other words, something or someone that is ignoble lacks honor. We would say that someone is being ignoble when they are doing something that they really should be ashamed of doing. There is, for example, a Bob Marley song in which he calls the apartheid government of South Africa "ignoble."
There are many things that are ignoble. You can use any of them to make a sentence. One example of such a sentence might be "my teacher and my parents scolded me, telling me that copying my homework from my friends was ignoble."