How do I compress a large PDF from a mac so I can send it VIA email?

Having a hard time finding MAC compression files, does any one have a suggestion? Its 19MBS PDF. and my gmail is taking over an hour to upload it. I want to stop it because I dont know why it is taking so long and compress the file, I have ten others, Its a thesis, I need to send to the university, they only want PDF. And they are in another country so just making a CD is out of the question.