Recently in China, the English word "out" is more and more common among young people. While people want to say something or someone is out of date, they will use this word: out. In most of the cases, this word is to describe someone doesn't know something very popluar. Let's see some examples:

1. Someone + out + le.

eg: Nǐ out le. 

      你out了。

      You're out of date.

Chinese usually say this sentence in this kind of situation: what? you don't know Lady Gaga? Nǐ out le.

2. Something + out + le.

eg: Zhè tiáo qúnzi out le.

     这条裙子out了。

     This skirt is out of date.