Loo = toilet (also called lavatory - loo is a shortened version of this...).

Excuse me, is there anyone here that can tell me what the meaning of "loo" is in English?

That means bathroom in the UK I believe. Americans don't use that word, but they know what it means.

I'm guessing that you're talking about the word "loo." In the UK, you can say that word to mean the restroom (informally). That said, here in the US, people don't use that word at all.