ごめんなさい
ごめんなさい · gomennasai · JLPT N3 · noun
forgiveness
🙇 go + men + nasai = honourable pardon + please do: please pardon me
ご is a polite prefix, めん is 免, meaning exemption or pardon, and なさい is a polite command form of する (to do). So the literal sense is please grant me your honourable pardon. The casual short form is ごめん.