Wordorigins.org

Brothel derives, through the Middle English broþel, from the Old English bréoðan, meaning ruined or degenerate. It is a variant of the word brethel, meaning a good-for-nothing, a wretch.

The original sense was of a worthless or degenerate person and first appears in William Langland’s Piers Plowman, A text, which was written c.1367-70, with the surviving manuscripts dating to c.1390:

For nou is vche Boye, Bold Broþel, an[d?] oþer, To talken of þe Trinite, to beon holden A syre.
(For now is each boy (commoner), bold brothel, and other, to talk of the Trinity, to be looked upon as a sire.)

The phrase get down to brass tacks is of uncertain etymology. No one knows why it was originally coined, but there are several explanations. What we do know is that the phrase dates to at least the 1860s and that it is American, possibly Texas to be specific, in origin. Beyond that, there is only speculation.

The earliest known citations are from newspapers, the first being from the Houston, Texas Tri-Weekly Telegraph of 21 January 1863:

When you come down to “brass tacks"—if we may be allowed the expression—everybody is governed by selfishness.

Another early published use is from the Bangor, Maine Daily Whig & Courier of 12 January 1867:

The Galveston Bulletin says that Texas must “come down to brass tacks” and accept the constitutional amendment, unless the people wish Congress to proceed with reconstruction.

It is commonly asserted that brass tacks is Cockney rhyming slang for facts. It definitely is not British in origin, but it could be rhyming slang other than Cockney. This, however, is complicated by the variant brass nails, which dates to at least 1911. The variant doesn’t fit the rhyming slang, but then it may have been an alteration by someone who didn’t understand the rhyming slang. In any case, the rhyming slang explanation doesn’t appear until 1960, nearly a century after the appearance of the phrase, and is likely an after-the-fact attempt to make sense of the phrase.

Another explanation is that stores used to mark out a yard on the counter with brass tacks so that customers buying cloth could measure it by getting down to brass tacks and ensure they weren’t being cheated.

Yet another is that brass tacks were used as a foundation for upholstery. So getting down to brass tacks meant getting down to basics.

Sources: ADS-L; Oxford English Dictionary, 2nd Edition; Historical Dictionary of American Slang; New Partridge Dictionary of Slang)

The adjective blue has been associated with despondency and sadness since the 16th century. The noun the blues has been with us since 1741, when English actor David Garrick penned the following in a letter:

I am far from being quite well, tho not troubled w^th y^e Blews as I have been.

The blues is a shortening of blue devils, demons popularly thought to cause depression and sadness. Blue devils have been around since at least 1616, from Times’ Whistle, a collection of satirical poems from that year:

Alston, whose life hath been accounted evill, And therfore cal’de by many the blew devill.

The glossary to that work has an entry for:

Devil, blew devill, 107/3443. “Blue devils,” the “horrors,” or the remorse which frequently follows an ill course of life.

The name of the musical style has been around since 1912, taking its name from the mournful and haunting nature of the lyrics. Some sources say the style takes its name from the blue notes that it uses, blue notes being a minor interval in place of a major, an off-pitch note. But the opposite is true. Blue notes get their name from the blues, not the other way around. Blue note is attested to in 1919.

(Source: Oxford English Dictionary, 2nd Edition; Google Books)

Blackmail derives from the old practice of clan chieftains who ran protection rackets against farmers in the Scottish-English border counties. If the farmers did not pay the mail, the chiefs would steal their crops and cattle. This sense of mail is from Old English meaning rent or tribute and ultimately comes from the Old Icelandic mál, meaning speech or agreement. (This is one of those Old English words introduced by Viking raiders.) This sense is unrelated to other senses of mail and is now obsolete except for its use in blackmail.

One of the more frequently asked questions on this site’s discussion group is where the term two bits comes from. Most people know that two bits are worth 25 cents, but the origin is a mystery to them.

Bit, which ultimately comes from the Old English bita, originally meant a morsel of food. From there it went on to denote any small thing, particularly a fraction of a larger whole. By the beginning of the 17th century, bit had become a thieves’ cant term for money. In 1607, Thomas Dekker, a 17th century comic writer, penned the following in his 1607 Jests to Make You Merie:

If they ... once know where the bung and the bit is, so much as to say your purse and the money…

By 1683 in the English-speaking American colonies bit had come to specifically denote a Spanish/Mexican real, or one eighth of a peso (the famed pieces of eight). The Colonial Records of Pennsylvania of that year record the following:

Their Abuse to y^e Governm^t, in Quining of Spanish Bitts and Boston money.

The Spanish peso was a common form of currency in the colonies. And in the early days of the United States, pesos were commonly used as dollar coins and real coins represented twelve and half cents, hence two bits equaled 25 cents.

(Source: Oxford English Dictionary, 2nd Edition)