回单儿 Traditional form: 回單兒 Pinyin (reading): huídānr Definitions: erhua variant of 回單/回单 (huídān) Characters: 回 - to return, to turn around; a time 单 - single, individual, only; lone 儿 - son, child Traditional characters: 回 - to return, to turn around; a time 單 - single, individual, only; lone 兒 - son, child