Latin: Petitio Principii
Begging the Question is circular logic in which an essential premise to the conclusion is itself, stated without support. It has nothing to do with begging for a question, as in common misuse. The "question" is the matter or subject at hand, and the "begging" can be thought of a metaphorical attempt to get it for free. The Latin petitio principii with the English cognate "petitioning the principle" is more appropriate but less colorful.