Oh! Definitely it has a lot of meanings. Thank you Jutta and Norman!

On top of the meanings Norman mentioned, it can also be used as an adverb used with an adjective, meaning something like "relatively", as for example "His house was rather big." or "He was driving rather fast". It is a bit of an understatement thing. What you mean is: "He was going really fast", but it would be slightly impolite or direct to say it, so you use "rather" instead. I think it is probably more of a British thing to use it in this way than an American one.

"Rather you than me" means I am glad I am not in your shoes. For example: You "I am going parachuting tomorrow". Me: "Rather you than me". "I'd rather not get involved" means I do not wish to be involved in a situation. "Rather!" can mean I agree with you. "Do you think I am on the right track?" "Rather!" This gives you 3 other examples. No doubt there are more.