Boy:
Do you know how to spell "cowboy"? 

你知道怎么拼写单词“牛郎”吗?
Girl:
Yes, C-O-W-B-O-Y. 

知道,C-O-W-B-O-Y。
Boy:
What's it's meaning in Chinese? 

这个单词中文是什么意思呢?
Girl:
It means a boy who is living on feeding cows.And it always refers to a certain character in Chinese fairy story. 

牛郎指的是以放牛为生的人,通常特指中国古代神话中的一个人物。