disgrace
A loss of respect because of shameful or bad behavior.
Disgrace means the loss of respect and honor, often because of shameful behavior. When someone falls into disgrace, others who once admired them now feel disappointed or even angry about what they've done.
A student who gets caught cheating on an important exam might feel disgraced in front of classmates and teachers. A politician who lies to the public falls from grace and loses people's trust. The word captures that heavy feeling when someone's reputation crumbles because they did something wrong.
You can also use disgrace to describe something that brings shame: “The broken playground equipment is a disgrace to our school” means it reflects poorly on everyone. When you say someone disgraced themselves, you mean they behaved so badly that they damaged their own reputation.
The opposite of disgrace is honor or esteem. While everyone makes mistakes, disgrace usually involves a serious betrayal of trust or duty, something that makes others question your character. A disgraceful action is one that brings shame, like abandoning a friend who needs help or breaking an important promise.