apologetic, excusatory
If you are contrite, you are sorry for whatever you have done. Sorry is one synonym. You might also hear someone say they feel remorse, or they are remorseful. Another term you might use would be apologetic. Repentant is another good synonym.
He looked at her with an apologetic expression, realizing he had made a mistake.
aplogize
Apologetic
It is apologetic.
Ferromagnet
Apology
apologetic
Negative Apologetics
stick kick lick sick pick
The adjective related to the noun apology is apologetic.