Update on “boof” 10/10/2018
The controversy on the true meaning of boof continues online. This time an article from the Quartz, offers the following insight which was sorely missing in the Vox article.
Before quoting the relevant excerpt, I should explain I do not have a subscription to the OED (The Oxford English Dictionary).
According to the OED, a boof [in its original form] is “a blow that makes a sound like a rapid, brief movement of air.” The onomatopoeic word’s first known appearance in the English language, as the OED tells it, is an 1825 reference in the Supplement to the Etymological Dictionary of the Scottish Language.
Although unrelated to the modern slang meaning of "boof", its original significance is remarkably similar to that of “boff” mentioned by the New Collegiate Dictionary.