Proper is actually a word you can use all by itself, you can just expostulate "Proper!" and it means something similar to "Wicked!" or "Excellent!" or "Cool!". It is an exclamative word. If something totally cool or awesome happens you just say "Proper!" and it means the same as "Awesome!" or "Cool!", but it is much newer and fresher and better and longer-lasting than those words. Its literal definition is "Perfect". Say this if you want to not only be with it, but way, way ahead of it. Proper.