Oh, thank you all...But it's just as a word in the book, and it gives a meaning in Chinese which is called 雅语(But there isn't ny context, just a 'word'-아어!) and it really confused me. I don't think there's a word called 雅语 in Chinese just like you don't think it has a meaning in Korean as well... So...It's not a word...

First, when you ask the meaning of a word or phrase (or even grammar), you should always include context. Second, based on the context you ended up giving, I suspect you may be referring to grammar (아/어) rather than vocabulary.

'아어' doesn't have any meaning as far as I know. It's kind of a,e,i,o,u in alphabet.

@Max: Hello. Thanks for your commet. I've seen the word from a language book of Korean. So doesn't it have an exact meaning?

I was squeezing my head, but still don't get what '아어' is. More explanation of the situation would be very helpful.