Wordorigins.org

Four times a year, American television viewers are subjected to sweeps periods. The sweeps are when the A.C. Nielsen Company measures the audiences in all 210 US television markets.  Nielsen continuously measures national programming, but local audiences are only measured in November, February, May, and July-August. The ratings gathered during these periods are used to set ad-rates and to make decisions about local programming. During sweeps months, the networks schedule new episodes of programs, specials, original productions, and other shows that are likely to draw a larger-than-ordinary audience. In non-sweeps months, viewers get a lot of reruns.

The measurement of these local markets was not begun by Neilsen, but rather by a competitor, the American Research Bureau, now known as Arbitron. By 1961 Arbitron was measuring every television market in America at least twice a year. It comes from the metaphor of sweeping up or gathering the data. From Newsweek, 30 November 1970:

There is a temptation to look one’s best during sweeps, but the practice of “loading,” or temporarily beefing up programming, is specifically forbidden by Federal unfair-competition regulations.

(Source: Oxford English Dictionary, 2nd Edition)

There is a legend, stemming from ancient myth, that swans sing an exquisitely beautiful song just before dying. There’s no truth to it, but that’s the legend and the origin of the phrase. From Ovid’s Metamorphoses (14:426-430):

ultimus adspexit Thybris luctuque viaque fessam et iam longa ponentem corpora ripa. illic cum lacrimis ipso modulata dolore verba sono tenui maerens fundebat, ut olim carmina iam moriens canit exequialia cycnus.
(Tiber was last to see her, as she lay down, weary with grief and journeying, on his wide banks. There, she poured out her words of grief, tearfully, in faint tones, in harmony with sadness, just as the swan sings once, in dying, its own funeral song.)

In English, literary allusions to the legend date back to Chaucer’s Anelida and Arcite, c. 1374:

Þe swane...Ageynist his dethe shall synge his penavnse.
(The swan...against his death shall sing his penance.)

The phrase swan song itself appears in the early 19th century. The English phrase is a calque of the German Schwanengesang, which was the name of a posthumous collection of Franz Schubert’s music, published in 1828. The English phrase first appears a few years later in Thomas Carlyle’s 1831 Sartor Resartus:

The Phoenix soars aloft,...or, as now, she sinks, and with spheral swan-song immolates herself in flame.

(Sources: Oxford English Dictionary, 2nd Edition; Ovid, Metamorphoses (Kline) 14: 397-434: The Fate of Canens, the Ovid Collection, Univ. of Virginia E-Text Center, University of Virginia.)

This term refers to a car big enough to haul people and luggage to and from a railway station. Originally, station wagon referred to horse-drawn carriages. From the Hub News of 23 May 1894:

Business has been fairly good this spring...Traps are in most demand, next come buggies, cutunders, and business rockaways or station wagons.

By 1904 the term was being used in reference to automobiles. From Motor World of 21 January of that year:

The station wagon is a new model exhibited the first time this year.

The British equivalent of the term, estate car, is much more recent. It only dates to 1950. From Motor Industry of July of that year:

Latest car price list...Standard...Vanguard saloon...Estate car.

(Source: Oxford English Dictionary, 2nd Edition)

What is a stool pigeon? Does it refer the bird’s habit of defecating on statues? Does it have something to do with furniture?

Stool does not refer to the piece of furniture or to dung. It is a variant of stale, meaning decoy. It comes from the Anglo-Norman estale or estal, a decoy bird used to entice a hawk to fly into a net. The French word probably originally derives from the Germanic steall meaning a place or standing position, or in this case a stationary bird. The root is also the source of the modern stall. From the c.1440 Anglo-Latin lexicon Promptorium Parvulorum Sive Clericorum:

Stale, of fowlynge or byrdys takynge, stacionaria.
(Stale, of fowling or birds taking, stacionaria.)

This term arose in engineering circles. The earliest known usage is from 1910, in H.H. Suplee’s Gas Turbine:

It has therefore been thought desirable to gather under one cover the most important papers...In the present state of the art this is all that can be done.

There is a somewhat older use of status of the art dating to 1889 in Anthony’s Photography Bulletin:

The illustrations give a good idea of the present status of the art in the various methods of printing.

(Source: Oxford English Dictionary, 2nd Edition)

Dickson, Paul (2006). Slang: the topical dictionary of Americanisms. New York, Walker and Company.

Slang terms organized by topic. Primarily definitions, little etymological info.

This word for a celestial ball of flaming hydrogen dates back to the Old English word steorra. From the Vespasian Psalter, c.825:

Hergað hine alle steorran & leht.
(Plundered him all the stars & light.)

Squaw is borrowed from the Narragansett word for woman and has cognates in the other Algonquin languages. It appears in English in 1634, shortly after the first European settlements in New England. From William Wood’s 1634 New Englands Prospect:

If her husband come to seeke for his Squaw.

Squaw is not, as is sometimes claimed, a Native American word meaning either prostitute or vagina. However, it is still considered by many to be offensive in the same way that addressing an English-speaking female by the word woman is offensive and non-Algonquin Indians may be offended by it because it is not a word in their language—like calling a Frenchwoman Frau.

(Source: Oxford English Dictionary, 2nd Edition)

Square meal is an Americanism. It comes from the adjectival use of square to mean sturdy or substantial. There are older, related senses of the adjective square. In the 17th century, for example, square was used to describe someone who could eat and drink copious amounts. From Randle Cotgrave’s 1611 Dictionarie of the French and English Tongues:

Vn ferial beuveur, a square drinker, a faithfull drunkard; one that will take his liquor soundly.

And from Beaumont and Fletcher’s Bonduca from c.1616:

By —— square eaters, More meat I say:...how terribly They charge upon their victuals.

The term square meal itself appears in the late 1860s, but does not become common until the 1880s. From the magazine All Year Round of 19 September 1868:

Roadside hotel-keepers...calling the miners’ attention to their “square meals:” by which is meant full meals.

There are various stories relating this phrase to the types of food (usually four in number) consumed. These stories are not true.

The style of eating, dubbed square meal and once required of plebes, first year cadets, at West Point, where eating utensils must be moved at right angles is derivative of the common usage, not the origin.

(Source: Oxford English Dictionary, 2nd Edition)

This word for potato comes from the digging implement used to uproot them. The word is of unknown origin and was originally used as a term for a short knife or dagger. This sense dates to the 15th century. From Promptorium Parvulorum Sive Clericorum, an Anglo-Latin lexicon from c.1440:

Spudde, cultellus vilis.
(Spudde, an inexpensive little knife)

Over time, spud came to mean a digging tool. From Samuel Pepys Diary of 10 October 1667:

We...begun with a spudd to lift up the ground.

Eventually the word changed in meaning, transferring to the potato from the tool used to dig the tubers up. From Edward Wakefield’s 1845 Adventure in New Zealand:

Pigs and potatoes were respectively represented by ”grunters” and ”spuds.”

An avid reader emailed me with a supposed acronymic origin of spud. The reader rightly was skeptical, but had found the reference in Mario Pei’s 1949 The Story of Language. Pei writes, “the potato, for its part, was in disrepute some centuries ago. Some Englishmen who did not fancy potatoes formed a Society for the Prevention of Unwholesome Diet. The initials of the main words in this title gave rise to spud.” Like all other pre-20th century acronymic origins, this one is false. This just goes to show you, that even language professionals can get taken in sometimes.

(Source: Oxford English Dictionary, 2nd Edition)