This is the 4228th most frequent Japanese word.
代行
"代行" means "acting on behalf of" or "substitute service."
代行 refers to providing agency services for someone or acting on their behalf in arranging travels.
彼は旅行代行サービスを提供しています。
He provides travel agency services.
代行 refers to substituting or acting on someone's behalf, in this case as a driver.
雨の日には代行運転を利用します。
On rainy days, I use the driver substitute service.
代行 refers to delegating or acting in administrative roles for another entity.