What is the real etymology of "China"?
Update, I think I misunderstood, the question is about the word "China" in English while I was talking about the word "China" in Chinese.

This is a question which has no exact answer to. The most popular answer is, it comes from the pronunciation of "秦" in English, which is "chin". Other answers think it may come from how Indians call Chinese, which is "chini". There are many other answers and each has its own explanation. It you are interested, please check out 百度百科。

I will answer this question to the best of my knowledge, in Chinese, 抛砖引玉，如有不到的地方，还请见谅。

Since this is a complicated subject and it would be hard to give explanation of 中华 in English, this answer will be in Chinese.

题注所言“秦”或“汉”皆是封地之名，如“汉”，就是由水流之声而得名的。而“中华”，则与前两者不同，“中”的意思是中央，也即中央之地，而“华”的意思是美好。是汉初河南因文化美好、社会昌平而得名的，后来成为整个中华王朝的名称。

而“汉”，则成为了中华民族的名称，“唐”，另一个繁盛的中华王朝，则成为了海外华人称呼自身聚居地的名词，即唐人街。

中国历史上，不少统一王朝的名称都来源于之前藩王的封地名称，如“汉”来自于刘邦的封地，“唐”来源于李渊的封地等。

中国历史上还有一些类似的王朝名称后来被引作它用的例子，如，相传，农历是夏朝时发明的，所以，农历曾经也叫夏历，还有，商朝人善做生意，所以做生意的人叫做商人等等。