* Definição:
An honorary degree (Latin: honoris causa ad gradum) is an extra-ordinary academic degree awarded to an individual as a decoration, rather than as the result of matriculating and studying for several years. An honorary degree may be conferred by an institution that the recipient never attended. The degree itself may be a bachelor's, master's or doctorate degree – the last being by far the most common.
http://en.wikipedia.org/wiki/Honorary_degree

* Do Houaiss:
honoris causa - a título honorífico [É título laudatório e homenageante, conferido a pessoa sem que esta tenha passado por quaisquer exames ou concursos.]
Ex.: doutor honoris causa.