1.Used to take the piss out of an individual who thinks their hard.
2.Also can be used as a term of endearment, in a similar fashion to " boi" or " boss"
A Paul is someone who really know's what to say to a Catherine so i think they would get on well. a Paul is something that everyone has to love. He is a quite handesome creature. a Paul is a very brave & curageous indidual and no one can be like Paul ... ever!