The Doctor is a Time Lord from the planet Gallifrey. He has a blue box called the TARDIS (Time And Relative Dimensions In Space), the TARDIS is a Time Machine which goes anywhere in Time And Space. Time Lords have a little thing called regeneration where the Time Lord changes appearance but keeps most mental thoughts.

To call someone "The Doctor" the individual must have extreme knowledge of one topic, so if someone was smart you'd say -

The man who makes sure you living and in perfect health. They work 24/7 and save people's lives and what do they get? Hate

n. People who get paid to feel you up and stick needle into your exposed flesh for a living. Though it sounds like a good deal, to be one, you have to waste about 8 years of your life in college plus god-knows how many more years in med school. Being a doctor takes a massive toll on your mental health- They are tasked with having to tell people when they have an incurable disease, tell people that they can't have babies, and don't forget the occasional Colonoscopy!

A med school graduate

Somehow commands a level of prestige in society beyond his means.

Scary. Very scary. Smiles, stabs you with needles, tells you everything is fine but it's really not...

a person who kills your ills with pills then kills you with bills

A qualified practitioner of medicine; a physician.