apologetic

US /əˌpɑː.ləˈdʒet̬.ɪk/
UK /əˌpɑː.ləˈdʒet̬.ɪk/
1.

xin lỗi

showing that you feel sorry about having caused someone problems or unhappiness:

:
She was so apologetic about forgetting my birthday it was almost embarrassing.