popular name of a common bird of Europe, Asia, and America, known for its chattering, acquisitiveness, curiosity, and mimicry, c. 1600, earlier simply pie (mid-13c.).
The first element is Mag, nickname for Margaret, long used in proverbial and slang English for qualities associated generally with women, especially in this case "idle chattering" (as in Magge tales "tall tales, nonsense," early 15c.; also compare French margot "magpie," from Margot, pet form of Marguerite). The name Margaret, and its reduced forms Mag, Madge, diminutive Maggie, also has long been familiarly applied to birds. Pies were proverbial since Middle English for chattering (as were jays), hence the application of pie to a prattling gossip or tattler, also "sly person, informer" (late 14c.) and in 15c.-16c. a wily pie (or wyly pye) was "a cunning person."
The second element, pie, is the earlier name of the bird, from Old French pie, from Latin pica "magpie" (source also of Spanish pega), fem. of picus "woodpecker," from PIE root *(s)peik- "woodpecker, magpie" (source also of Umbrian peica "magpie," Sanskrit pikah "Indian cuckoo," Old Norse spætr, German Specht "woodpecker"); possibly from PIE root *pi-, denoting pointedness, of the beak. The application to pies might be because the magpie also has a long, pointed tail.
The birds are proverbial for pilfering and hoarding and for their indiscriminate appetites (see pica (n.2)); they can be taught to speak, and have been regarded since the Middle Ages as ill omens.
Whan pyes chatter vpon a house it is a sygne of ryghte euyll tydynges. 
Divination by numbering magpies is attested from c. 1780 in Lincolnshire; the rhyme varies from place to place, the only consistency being that one is bad, two are good.
The councils which magpies appear to hold together, at particular seasons, commonly called "folkmotes," are associated in the minds of many with superstitious and ominous notions. The innocent objects of terror, while meeting together most probably for the purpose of choosing mates, are supposed to be conspiring and clubbing their wits, for the weal or woe of the inhabitants of the neighbouring village. If they are of an even number and carry on their cheerful, noisy chatter, it is supposed to betoken good to old and young—but if there is an odd magpie perched apart from the rest, silent, and disconsolate, the reverse of this is apprehended, and mischievous consequences are inevitably expected. [The Saturday Magazine, Jan. 23, 1841]
Middle English setten, from Old English settan (transitive) "cause to sit; make or cause to rest as on a seat; cause to be put, placed, or seated;" also "put in a definite place," also "arrange, fix adjust; fix or appoint (a time) for some affair or transaction," and "cause (thoughts, affections) to dwell on."
This is from Proto-Germanic *(bi)satejanan "to cause to sit, set" (source also of Old Norse setja, Swedish sätta, Old Saxon settian, Old Frisian setta, Dutch zetten, German setzen, Gothic satjan), causative form of PIE *sod-, a variant of the root *sed- (1) "to sit." Also see set (n.2). It has been confused with sit (v.) at least since early 14c.
The intransitive sense of "be seated" is from c. 1200; that of "sink down, descend, decline toward and pass below the horizon" (of the sun, moon, or stars) is by mid-13c., perhaps from similar use of the cognates in Scandinavian languages; figurative use of this is from c. 1600.
Many uses are highly idiomatic, the verb, like put, its nearest equivalent, and do, make, get, etc., having become of almost universal application, and taking its distinctive color from the context. [Century Dictionary]
The sense of "make or cause to do, act, or be; start, bring (something) to a certain state" (on fire, in order, etc.) and that of "mount a gemstone" are attested by mid-13c. That of "determine upon, resolve" is from c. 1300; hence be set against "resisting" (mid-14c.).
The sense of "make a table ready for a meal" is from late 14c.; that of "regulate or adjust by a standard" (of a clock, etc.) is from late 14c. In printing, "to place (types) in the proper order for reading; put into type," 1520s. From c. 1500 as "put words to music." From 1570s as "put (a broken or dislocated bone) in position." In cookery, plastering, etc., "become firm or solid in consistency" by 1736.
To set (one's) heart on (something) is from c. 1300 as "love, be devoted to;" c. 1400 as "have a desire for." To set (one's) mind is from mid-15c.; transitive set (one's mind) to "determine to accomplish" is from late 15c. To set (something) on "incite to attack" (c. 1300) originally was in reference to hounds and game. To set an example is mid-14c. (set (v.) in the sense of "present" is from late Old English). The notion of "fix the value of" is behind old phrases such as set at naught "regard as nothing."
To set out is from c. 1300 as "display (for sale);" to set up shop "commence doing business" is from c. 1400.
eighteenth letter of the English alphabet, traceable to Phoenician and always representing more or less the same sound, which in many languages is typically so resonant and continuous as to be nearly akin to the vowels, but in English is closer to -l-.
It was aspirated at the start of words (hr-) in Old English, as in Greek, but this was abandoned in English spelling and pronunciation by the end of the Old English period, but the rh- spelling survives in many words borrowed from Greek. In many languages and some dialects (e.g. Scottish) it is pronounced with a distinct trilling vibration of the tongue-tip, which gave it its ancient nickname of "the dog letter;" in other regional dialects (e.g. Boston) it is omitted unless followed by a vowel, while in others it is introduced artificially in pronunciation ("idear," "drawring").
If all our r's that are written are pronounced, the sound is more common than any other in English utterance (over seven per cent.); the instances of occurrence before a vowel, and so of universal pronunciation, are only half as frequent. There are localities where the normal vibration of the tip of the tongue is replaced by one of the uvula, making a guttural trill, which is still more entitled to the name of "dog's letter" than is the ordinary r; such are considerable parts of France and Germany; the sound appears to occur only sporadically in English pronunciation. [Century Dictionary]
Louise Pound ("The Humorous 'R'") notes that in British humorous writing, -ar- "popularly indicates the sound of the vowel in father" and formations like larf (for laugh) "are to be read with the broad vowel but no uttered r."
The moment we encounter the added r's of purp or dorg in our reading we know that we have to do with humor, and so with school-marm. The added consonants are supposed to be spoken, if the words are uttered, but, as a matter of fact, they are less often uttered than seen. The words are, indeed, largely visual forms; the humor is chiefly for the eye. [Louise Pound, "The Humorous 'R,'" American Mercury, October 1924]
She also quotes Henry James on the characteristic prominence of the medial -r- sound (which tends to be dropped in England and New England) in the speech of the U.S. Midwest, "under some strange impulse received toward consonantal recovery of balance, making it present even in words from which it is absent, bringing it in everywhere as with the small vulgar effect of a sort of morose grinding of the back teeth."
In a circle, meaning "registered (trademark)," attested by 1925. R&R "rest and relaxation," is attested by 1953, American English; R&B "rhythm and blues" (type of popular music) is attested by 1949, American English. Form three Rs, see Three Rs.