jungle (n.)youdaoicibaDictYouDict[jungle 词源字典]
1776, from Hindi jangal "desert, forest, wasteland, uncultivated ground," from Sanskrit jangala-s "arid, sparsely grown with trees," of unknown origin. Specific sense of "land overgrown by vegetation in a wild, tangled mass" is first recorded 1849; meaning "place notoriously lawless and violent" is first recorded 1906, from Upton Sinclair's novel (compare asphalt jungle, 1949, William R. Burnett's novel title, made into a film 1950 by John Huston; blackboard jungle, 1954, Evan Hunter's novel title, movie in 1955). Jungle gym was a trademark name, 1923, by Junglegym Inc., Chicago, U.S. Jungle bunny, derogatory for "black person," attested from 1966.[jungle etymology, jungle origin, 英语词源]
rare (adj.1)youdaoicibaDictYouDict
"unusual," late 14c., "thin, airy, porous;" mid-15c., "few in number and widely separated, sparsely distributed, seldom found;" from Old French rere "sparse" (14c.), from Latin rarus "thinly sown, having a loose texture; not thick; having intervals between, full of empty spaces," from PIE *ra-ro-, from root *ere- "to separate; adjoin" (cognates: Sanskrit rte "besides, except," viralah "distant, tight, rare;" Old Church Slavonic rediku "rare," Old Hittite arhaš "border," Lithuanian irti "to be dissolved"). "Few in number," hence, "unusual." Related: Rareness. In chemistry, rare earth is from 1818.
sparse (adj.)youdaoicibaDictYouDict
1727, from Latin sparsus "scattered," past participle of spargere "to scatter, spread," from PIE root *(s)preg- (2) "to jerk, scatter" (cognates: Sanskrit parjanya- "rain, rain god," Avestan fra-sparega "branch, twig," literally "that which is jerked off a tree," Old Norse freknur "freckles," Swedish dialectal sprygg "brisk, active," Lithuanian sprogti "shoot, bud," Old Irish arg "a drop"). The word is found earlier in English as a verb, "to scatter abroad" (16c.). Related: Sparsely; sparseness.