contrite
Feeling truly sorry and regretful for doing something wrong.
Contrite means genuinely sorry for something wrong you've done, feeling true regret for your actions and the harm you caused. When you're contrite, you understand the wrongness of what you did and feel weighed down by real remorse.
There's a big difference between being contrite and just mumbling “sorry” to avoid punishment. A contrite apology shows real remorse: you understand why what you did was wrong, you feel genuinely bad about it, and you want to make things right. If you accidentally broke your sister's favorite toy and feel terrible about it, explaining what happened and offering to help fix it or replace it shows you're contrite.
Teachers and parents can usually tell the difference between a student who's truly contrite and one who's just going through the motions. Being contrite doesn't erase what happened, but it's a necessary first step toward making amends and rebuilding trust with people you've hurt or disappointed.