Wiktionary
n. A logical fallacy in which a premise of an argument contains a direct or indirect assumption that the conclusion is true; offering a circular argument; circular reasoning. vb. (context informal English) (present participle of beg the question English)
Wikipedia
To beg a question means to assume the conclusion of an argument—a type of circular reasoning. This is an informal fallacy, in which an arguer includes the conclusion to be proven within a premise of the argument, often in an indirect way such that its presence within the premise is hidden or at least not easily apparent.
The term "begging the question", as this is usually phrased, originated in the 16th century as a mistranslation of the Latin , which actually translates as "assuming the initial point". In modern vernacular usage, "to beg the question" is sometimes used to mean "to invite the question" (as in "This begs the question of whether...") or "to dodge a question". These usages are often criticized as being mistaken.
Usage examples of "begging the question".
Lytol approached Jaxom slowly, his eyes on the young man's face, begging the question.
And this was all begging the question of what my mother would think.
Unless you start by begging the question, there is nothing intrinsically unlikely in the existence of angels or in the action ascribed to them.