Doctor, as a title, originates from the Latin word of the same spelling and meaning. The word is originally an agentive noun of the Latin verb docere 'to teach'. It has been used as an honored academic title for over a millennium in Europe, where it dates back to the rise of the first universities. This use spread to the Americas, through its former European colonies, and is now prevalent in most of the world. Contracted "Dr" or "Dr.", it is used as a designation for a person who has obtained a Research Doctorate (i.e. Ph.D., Ed.D). In contrast, a degree such as M.D. and D.O. is a vocational degree, and thus not considered a doctorate.