When in 1887 James Murray was compiling entries beginning with the letter B for what was then called the New English Dictionary on Historical Principles, now the Oxford English Dictionary, he was able to find only two examples of blatteroon, both from the seventeenth century. It had been taken from the Latin blatero, a babbler, to generate an insult which Thomas Blount defined in his Glossographia of 1656 as “a babbler, an idle-headed fellow”.
So might the word have ended its life, but a small number of other examples are known, used without any elaboration for a person who won’t shut up. Dr Murray could not have known of them, as they are later than the publication of his dictionary entry. It seems that his inclusion of the word sparked a minor revival in its fortunes, and not solely in those works of a superficial and fleetingly entertaining nature designed merely to display the oddities of English.
This is one modern appearance, in a humorously verbose encomium studded with Yiddishisms that was published to mark the retirement of an eminent US legal expert:
Yale Kamisar’s acute logorrhea ... is well known to all. The only uncertainty, it seems, concerns the magnitude of the problem; some but certainly not all would go so far as to label him a blatteroon, a verbomaniac, or even a pisk or a plyoot.
Wayne R LaFave, in the Michigan Law Review, Aug 2004. Pisk is Yiddish for a garrulous speaker; a plyoot is a loudmouth.
The other curiosity is the appearance of the word in a variety of commercial code books. These weren’t designed to hide the sense of messages — the books were published for all to read who could beg, buy, borrow or steal a copy — but to provide one-word equivalents for common phrases to reduce the cost of cablegrams. Lieber’s code of 1896 said blatteroon meant “did you reserve?”; the New General and Mining Telegraph Code of 1903 translated it as “almost certain to float”; while the Western Union Telegraphic Code of 1901 left its meaning blank for sender and recipient to select their own.
Would blatteroon have appeared in any of these works without its having first been recorded in the NED? It’s very unlikely.