Arctic CircleyoudaoicibaDictYouDict[Arctic Circle 词源字典]
1550s, in reference to a celestial circle, a line around the sky which, in any location, bounds the stars which are ever-visible from that latitude (in the Northern Hemisphere, this is focused on the celestial north pole); the concept goes back to the ancient Greeks, for whom this set of constellations included most prominently the two bears (arktoi), hence the name for the circle (see arctic). Of Earth, the circle 66 degrees 32 minutes north of the equator, marking the southern extremity of the polar day, it is recorded from 1620s.[Arctic Circle etymology, Arctic Circle origin, 英语词源]
glasnost (n.)youdaoicibaDictYouDict
1972 (in reference to a letter of 1969 by Solzhenitsyn), from Russian glasnost "openness to public scrutiny," literally "publicity, fact of being public," ultimately from Old Church Slavonic glasu "voice," from PIE *gal-so-, from root *gal- (2) "to call, shout" (see call (v.)). First used in a socio-political sense by Lenin; popularized in English after Mikhail Gorbachev used it prominently in a speech of March 11, 1985, accepting the post of general secretary of the CPSU.
The Soviets, it seems, have rediscovered the value of Lenin's dictum that "glasnost," the Russian word for openness or publicity, is a desirable form of conduct. [New York Times news service article, March 1981]
musical (n.)youdaoicibaDictYouDict
"theatrical piece in which music figures prominently," 1937, from musical (adj.) in musical play. Earlier as a noun it meant "musical instrument" (c. 1500), "musical performance" (1570s); "musical party" (1823, a sense now in musicale).
prominent (adj.)youdaoicibaDictYouDict
mid-15c., "projecting, jutting out," from Latin prominentem (nominative prominens) "prominent," present participle of prominere "jut or stand out, be prominent, overhang," from pro- "before, forward" (see pro-) + minere "to project," from minae "projections, threats" (see menace (n.)). Meaning "conspicuous" is from 1759; that of "notable, leading" is from 1849. Related: Prominently.