“The mark of the blowhard is not simply to comment on areas outside his competence, but to do so publicly, with the weight of his reputation behind him, while not doing the appropriate background reading and refusing to seek the opinions of actual experts in the field before publishing. In doing so, the blowhard frequently makes mistakes that would be embarrassing even for those equipped with an undergraduate's knowledge of the area.”
Prof. Margaret M. Mitchell (pictured) of the University of Chicagohas written a scholarly assessment of the scholarly merits of the book Zealot in the article "L'Affaire Aslan." It is very well stated, very succinct. While the description above isn't necessarily the dictionary meaning of "blowhard", Mitchell's "L'Affaire Aslan" points out problems with Zealot that educated people should have spoke up about long ago, and casts serious doubt on Reza Aslan's claim to expertise in the field of New Testament history and Second Temple Judaism. Of course, it is another question entirely whether Aslan's Zealot would have value as the work of an amateur. Having demanded that the public treat his book as the objective and critical scholarship of an expert in the subject matter, Aslan doesn't have the luxury of being judged by that lower standard. "L'Affaire Aslan" was written by a someone who can more credibly be taken as an expert in the relevant topics.