Why is it called horoscope? Isn't the word "nine" still missing?

Wrong, it is used to describe a boy marrying a girl. Generally, a feudal family will show the fortune teller the date of birth of both parties, that is, the "eight characters" you mentioned above, whether men and women get married before they get married. But the eight characters you said are usually used in marriage, which means that it has not been shown to fortune tellers, and parents may not agree, which means it is too early.