The Latin sense shift in auster, if it is indeed the same word other Indo-European languages use for "east," for which Latin uses oriens (see Orient (n.)), perhaps is based on a false assumption about the orientation of the Italian peninsula, "with shift through 'southeast' explained by the diagonal position of the axis of Italy" [Buck]; see Walde, Alois, "Lateinisches etymologisches Wörterbuch," 3rd. ed., vol. I, p.87; Ernout, Alfred, and Meillet, Alfred, "Dictionnaire étymologique de la langue latine," 2nd. ed., p.94. Or perhaps the connection is more ancient, and from PIE root *aus- "to shine," source of aurora, which also produces words for "burning," with reference to the "hot" south wind that blows into Italy. Thus auster "(hot) south wind," metaphorically extended to "south."
1801, "one of the pieces with which the game of dominoes is played," from French domino (1771), perhaps (on a perceived resemblance to the black tiles of the game) from the earlier meaning "hood with a cloak worn by canons or priests over other vestments in cold weather" (1690s in English), from Latin dominus "lord, master" (from domus "house," from PIE root *dem- "house, household"), but the connection is not clear.
Metaphoric use in geopolitics dates to 1953, when U.S. President Eisenhower used the image in reference to what happens when you set dominoes upright in a row and knock the first one down. It came to be known as the domino theory.
President Eisenhower, on August 4, 1953, explained that if Indonesia fell, "the peninsula, the last little bit of land hanging on down there, would be scarcely defensible." "All India," he continued, "would be outflanked," and "Burma would be in no position for defense. On April 7, 1954, the President was still warning that if Indochina fell, all of southeast Asia would collapse like "falling dominoes." The President said, that as the last domino in the line falls inevitably from the toppling of the first, the loss of Indochina would lead to the loss of Burma, of Thailand, and Indonesia, and a threat to Australia and New Zealand. [Rep. Joseph R. McCarthy, Congressional Record, Aug. 2, 1955]
16th letter of the classical Roman alphabet, occurring in English only before a -u- that is followed by another vowel (with a few exceptions; see below), whether the -u- is sounded or not (pique). The letter is from the Phoenician equivalent of Hebrew koph, qoph, which was used for the deeper and more guttural of the two "k" sounds in Semitic. The letter existed in early Greek (where there was no such distinction), and called koppa, but it was little used and not alphabetized; it mainly served as a sign of number (90).
The connection with -u- began in Latin. Anglo-Saxon scribes at first adopted the habit, but later used spellings with cw- or cu-. The qu- pattern returned to English with the Normans and French after the Conquest and had displaced cw- by c. 1300.
In some spelling variants of late Middle English, quh- also took work from wh-, especially in Scottish and northern dialects, for example Gavin Douglas, Provost of St. Giles, in his vernacular "Aeneid" of 1513:
Lyk as the rois in June with hir sueit smell
The marygulde or dasy doith excell.
Quhy suld I than, with dull forhede and vane,
With ruide engine and barrand emptive brane,
With bad harsk speche and lewit barbour tong,
Presume to write quhar thi sueit bell is rong,
Or contirfait sa precious wourdis deir?
Scholars use -q- alone to transliterate Semitic koph or the equivalent in Turkish or Iranian (as in Quran, Qatar, Iraq). In Christian theology, Q has been used since 1901 to signify the hypothetical source of passages shared by Matthew and Luke but not in Mark; in this sense probably it is an abbreviation of German Quelle "source" (from Old High German quella, from the same Proto-Germanic source as Old English cwiella, cwylla"spring; well"). In Middle English accounts, it is an abbreviation of quadrans "farthing" (mid-15c.). In Roman personal names it is an abbreviation of Quintus.