A person who knows about the law, the loopholes in the law, and the Constitution (the Constitution has no loopholes), and will use any and all of the above to get you out of whatever stupid ass mess that your stupid ass got you into. You will love this person, until you pay them, when you will hate them, but at least you will be out of jail, unless you lost. A lawyer typically is an unhappy looking nerd typing on a blackberry, unless they work for the government, in which case they are harder to pinpoint.
Marc: Look at that lawyer, he scares me shitless with his knowledge of the law and the Constitution
Anne: What are you talking about, lawyers are just like us
Marc: What are you, on drugs?
Anne: (Hours later, after coming off high) Yes, I was. The cops arrested me for possession. I have to call my lawyer now