"collection of matching things," mid-15c., sette, sete, earlier "religious sect" (late 14c.), in part from Middle English set, past participle of setten (see set (v.)) and in part from Old French sette, sete "sequence," a variant of secte "religious community," from Medieval Latin secta "retinue," from Latin secta "a following" (see sect).
Skeat first proposed that set (n.), in the sense of "a number of things or persons belonging together" ultimately was a corruption of the source of sect, influenced by set (v.) in subsequent developments as if meaning "a number set together." Thus this noun set was in Middle English earliest in the sense of "religious sect," which also likely developed some modern meanings, such as "group of people" (mid-15c.), especially "persons customarily or officially associated" (1680s); "group of persons with shared status, habits, or affinities" (1777).
The meaning "a number of things having a resemblance or natural affinity; complete collection of pieces to be used together" is by 1560s. Hence, "collection of volumes by one author" (1590s), "complete apparatus for some purpose" (1891, of telephones, radio, etc.).
Meaning "group of pieces musicians perform at a club during 45 minutes" (more or less) is from c. 1925, though it is found in a similar sense from 1580s. Set-piece is from 1846 as "grouping of people in a work of visual art;" from 1932 in reference to literary works.
The word sett is a variant, preserved in old law and "now prevalent in many technical senses" [OED].
in the sports sense, 1879, originally in cricket, "taking three wickets on three consecutive deliveries;" extended to other sports c. 1909, especially ice hockey ("In an earlier contest we had handed Army a 6-2 defeat at West Point as Billy Sloane performed hockey's spectacular 'hat trick' by scoring three goals" ["Princeton Alumni Weekly," Feb. 10, 1941]). So called allegedly because it entitled the bowler to receive a hat from his club commemorating the feat (or entitled him to pass the hat for a cash collection), but the term probably has been influenced by the image of a conjurer pulling objects from his hat (an act attested by 1876). The term was used earlier for a different sort of magic trick:
Place a glass of liquor on the table, put a hat over it, and say, "I will engage to drink every drop of that liquor, and yet I'll not touch the hat." You then get under the table; and after giving three knocks, you make a noise with your mouth, as if you were swallowing the liquor. Then, getting from under the table, say "Now, gentlemen, be pleased to look." Some one, eager to see if you have drunk the liquor, will raise the hat; when you instantly take the glass and swallow the contents, saying, "Gentlemen I have fulfilled my promise: you are all witnesses that I did not touch the hat." ["Wit and Wisdom," London, 1860]
late 15c., "band attached to a letter with seals dangling on the free end," from French queue "a tail," from Old French cue, coe, queue, "tail" (12c., also "penis"), from Latin coda (dialectal variant or alternative form of cauda) "tail" (see coda, and compare cue (n.2)).
Also in literal use in 16c. English, "tail of a beast," especially in heraldry. A metaphoric extension to "line of dancers" (c. 1500) perhaps led to the extended sense of "line of people, etc." (1837), but this use in English is perhaps directly from French (queue à queue, "one after another" appears in early 19c. English and American military dictionaries).
If we look now at Paris one thing is too evident: that the Baker's shops have got their Queues, or Tails ; their long strings of purchasers arranged in tail, so that the first come be the first served,—were the shop once open! This waiting in tail, not seen since the early days of July, again makes its appearance in August. In time, we shall see it perfected, by practice to the rank almost of an art ; and the art, or quasi-art, of standing in tail become one of the characteristics of the Parisian People, distinguishing them from all other Peoples whatsoever. [Carlyle, "The French Revolution," 1837]
Also used 18c. in sense of "braid of hair hanging down behind" (attested by 1748), originally part of the wig, in later 18c. of the hair of the head.
QUEUE. From the French, which signifies tail; an appendage that every British soldier is directed to wear in lieu of a club. Regimental tails were ordered be nine inches long. [William Duane, "A Military Dictionary," Philadelphia, 1810]
late Old English pinn "peg or bolt of wood or metal used to hold things in place or fasten them together," from Proto-Germanic *penn- "jutting point or peak" (source also of Old Saxon pin "peg," Old Norse pinni "peg, tack," Middle Dutch pin "pin, peg," Old High German pfinn, German Pinne "pin, tack") from Latin pinna "a feather, plume;" in plural "a wing;" also "fin, scoop of a water wheel;" also "a pinnacle; a promontory, cape; battlement" (as in Luke iv.9 in Vulgate) and so applied to "points" of various sorts, from PIE root *pet- "to rush, to fly."
De Vaan and Watkins say Latin pinna is a derivative of penna, literally "feather" (see pen (n.1)); older theories regarded pinna as a separate word from a root meaning "sharp point." The Latin word also was borrowed in Celtic: Irish pinne "a pin, peg, spigot;" Welsh pin "a pin, pen."
The transition from 'feather' to 'pin' (a slender or pointed instrument) appears to have been through 'pen,' a quill, to ' pen,' a style or stylus, hence any slender or pointed instrument [Century Dictionary]
As a part of a lock or latch, c. 1200; as a control for a mechanical device, late 14c. The modern slender wire pin, used as a fastener for clothing or in sewing, is attested by this name by late 14c., perhaps late 13c. Transferred sense of "leg" is recorded from 1520s and holds the older sense. The meaning "wooden stick or club set up to be knocked down in a game" (skittles, bowling, etc.) is by 1570s.
Pin-money "annual sum allotted to a woman for personal expenses on dress, etc." is attested from 1620s. Pins and needles "tingling sensation" is from 1810. The sound of a pin dropping as a type of something all but silent is from 1775.
c. 1600, from Latin toga "cloak or mantle," from PIE *tog-a- "covering," suffixed form of root *(s)teg- "to cover." The outer garment of a Roman citizen in time of peace.
The toga as the Roman national dress was allowed to be worn by free citizens only. A stranger not in full possession of the rights of a Roman citizen could not venture to appear in it. Even banished Romans were in imperial times precluded from wearing it. The appearance in public in a foreign dress was considered as contempt of the majesty of the Roman people. Even boys appeared in the toga, called, owing to the purple edge attached to it (a custom adopted from the Etruscans) toga praetexta. On completing his sixteenth, afterward his fifteenth, year (tirocinium fori), the boy exchanged the toga praetexta for the toga virilis, pura, or libera—a white cloak without the purple edge. Roman ladies (for these also wore the toga) abandoned the purple edge on being married. [Guhl & Koner, "The Life of the Greeks and Romans," transl. Francis Hueffer, 1876]
Breeches, like the word for them (Latin bracae) were alien to the Romans, being the dress of Persians, Germans, and Gauls, so that bracatus "wearing breeches" was a term in Roman geography meaning "north of the Alps." College fraternity toga party was re-popularized by movie "Animal House" (1978), but this is set in 1962 and the custom seems to date from at least the mid-1950s.
Down on Prospect Street, Campus Club held a toga party, at which everyone wore togas. Charter held a come-as-you-are party, at which everyone wore what they happened to have on, and Cloister held a party called "A Night in Tahiti," at which we'd hate to guess what everyone wore. The borough police reported that only one false alarm was turned in. [Princeton Alumni Weekly, March 19, 1954]