ashamed
Feeling bad and embarrassed about something you did or are.
To feel ashamed means to feel embarrassed or guilty about something you did, something that happened to you, or some quality you have. When you're ashamed, you wish you could hide or undo whatever caused the feeling.
You might feel ashamed after getting caught lying to your parents, or after losing your temper and saying something mean to a friend. The feeling comes from knowing you acted badly or failed to live up to your own standards. Someone might also feel ashamed of a mistake they made in front of others, like tripping during a school presentation or forgetting their lines in a play.
Sometimes people feel ashamed of things that aren't actually their fault or aren't worth feeling bad about. A student might feel ashamed of their family's old car or worn-out clothes, even though there's nothing wrong with either. People try to tell the difference between shame that helps them do better (like feeling ashamed after cheating) and shame that just makes them feel small for no good reason.
When someone acts shamelessly, they do things that should embarrass them but don't seem to care. When someone is ashamed of themselves, they recognize they fell short of what they know is right.