To Bow
する verb
The quit ceremony is when you quit and are ready to go somewhere, so you bow and then get going. That's why this verb is to bow.
じぎする
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
日本人はどうしてペコペコお辞儀ばっかりするんですか？
Why do Japanese people bow so often?