expressionshistoryslang
I'm curious about the use/history of "hairy", as in Golly Dan, that was a pretty hairy math exam, wasn't it?
My dictionary sources identify two definitions unrelated to hair: the first can be summarized as "causing fright or anxiety", which I semi-confidently assume relates to "hair-raising"; the other is "difficult to deal with or comprehend" (from Merriam Webster). It's this latter that I'm curious about.
How did we come to say that something difficult is "hairy"?
"How come...we eat breakfast?" is less formal. As Robusto commented, it's a contraction of something like: "How does it come to be that ...?" or "How has it come to pass that...?"
Also, it's not as confrontational. "How come you turned up late?" is softer than "Why did you turn up late?". It is a subtle mechanism that allows us to drop the 'do' verb from the question.
The latter is something your boss might ask. It is a very direct question expecting a direct answer, with the emphasis on "you doing".
The former is something your work colleague might ask. It is softer because it acknowledges that 'it came to be' that you were late. The emphasis is shifted off "you doing".
On the origin of the expression “world’s oldest profession”, both etymonline and the wiktionary date its first recorded use to 1888. This would coincide with the use of the expression “the most ancient profession” by Rudyard Kipling in On the City Wall (1888):
Lalun is a member of the most ancient profession in the world. Lilith was her very-great-grandmamma, and that was before the days of Eve as every one knows. In the West, people say rude things about Lalun's profession, and write lectures about it, and distribute the lectures to young persons in order that Morality may be preserved. In the East where the profession is hereditary, descending from mother to daughter, nobody writes lectures or takes any notice; and that is a distinct proof of the inability of the East to manage its own affairs.
So, this is a relatively recent addition to the language (profession itself dates from circa 1200). I didn't find the exact first recorded use, but a Google ngram search clearly agrees that around 1890 is when the expression started to get widely used:
Before that, the expression had already been used and applied to other jobs, usually in pride. Some recorded uses that I could find include:
merchants, for which I will quote this Ditty in commendation of the Merchant-tailors’ Trade:
I have to concede that the point is nicely argued!
Other European languages have similar expressions, such as the French “le plus vieux métier du monde” (which translates exactly to the English).
On the issue of prostitution being or not a profession, I will quote the definition given by the New Oxford American Dictionary:
a paid occupation, esp. one that involves prolonged training and a formal qualification
So, prostitution is definitely encompassed into the broad scope of this definition. Moreover, in some countries, prostitution has a legal status that definitely classifies it as a regulated profession.
Best Answer
Robert Hendrickson, The Facts on File Encyclopedia of Word and Phrase Origins (1997) offers this analysis:
Eric Partridge, A Dictionary of Slang and Unconventional English (1961) confirms that the meaning of "hairy about the fetlocks," is "ill-bred, bad-mannered," and says that it comes "from the stables"; but he distinguishes that meaning of hairy (which he traces to the late 1890s) from the earliest meaning—"difficult"—which he says comes from Oxford University, circa 1850–1900.
An earlier work by Partridge, Slang To-day and Yesterday (1933) puts the dates for hairy as "difficult" as 1840–1870), suggesting that it had fallen into disuse by the turn of twentieth century:
John Farmer & William Henley, Slang and Its Analogues Past and Present (1893), also list "difficult" as the earliest slang meaning of hairy, and offer two early instances of that usage:
Other nineteenth-century meanings of hairy reported in Farmer & Henley include "Splendid; famous; conspicuous; uncommon" and [of women] "Desirable; full of sex."
None of the early editions of John Camden Hotten's Slang Dictionary (published in London between 1859 and 1874) contains any entry for hairy—even though hairy in the sense of "difficult" appears to be a survival of English university slang from roughly that era.