歉

Right 欠 - a pictograph of a person leaning back with mouth open, indexing 歉 in the open-mouth family: 歌 sing, 欢 cheer, 欲 desire, 吹 blow. 欠 specifically carries the 'lack, owe, be in debt' sense - exactly what an apology acknowledges. When you 道歉, you are admitting you owe someone something, even if only the right words.

Left 兼 supplies the sound: jiān drifting to qiàn with regular j/q alternation. Same phonetic powers 谦 modest, 嫌 dislike, 廉 incorrupt, 镰 sickle. 兼 depicts a hand holding two stalks of grain at once. Faintly semantic: an apology is doubling back to make amends for what was said.