cosmosyoudaoicibaDictYouDict
cosmos: [17] Cosmos is a learned borrowing from Greek kósmos. The underlying meaning of this was ‘order’, and it appears originally to have been applied to the world and the universe by Pythagoras and his school in reference to the orderliness of creation. In the mid 20th century the word provided a useful linguistic distinction between Western and Soviet activities in space, cosmonaut (from Russian kosmonavt) contrasting with astronaut.

Somebody who is cosmopolitan [19] is literally a ‘citizen of the world’, from Greek kosmopolítēs, a compound of kósmos and polítēs. From Greek kósmos ‘order’ was derived the verb kosmein ‘arrange, adorn’. This in turn provided the basis of the adjective kosmētikós ‘skilled in adornment’, which passed into English as cosmetic [17].
=> cosmetic, cosmopolitan
citizen (n.)youdaoicibaDictYouDict
early 14c., "inhabitant of a city," from Anglo-French citezein (spelling subsequently altered, probably by influence of denizen), from Old French citeien "city-dweller, town-dweller, citizen" (12c., Modern French citoyen), from cite (see city) + -ain (see -ian). Replaced Old English burhsittend and ceasterware. Sense of "inhabitant of a country" is late 14c. Citizen's arrest recorded from 1941; citizen's band (radio) from 1947. Citizen of the world (late 15c.) translates Greek kosmopolites.
cosmopolitan (adj.)youdaoicibaDictYouDict
1844, from cosmopolite "citizen of the world" (q.v.) on model of metropolitan. The U.S. women's magazine of the same name was first published in 1886. Cosmopolitanism first recorded 1828.
cosmopolite (n.)youdaoicibaDictYouDict
late 16c., "man of the world; citizen of the world," from Greek kosmopolites "citizen of the world," from kosmos "world" (see cosmos) + polites "citizen" (see politic). In common use 17c. in a neutral sense; it faded out in 18c. but was revived from c. 1800 with a tinge of reproachfulness (opposed to patriot).
mundane (adj.)youdaoicibaDictYouDict
mid-15c., "of this world," from Old French mondain "of this world, worldly, earthly, secular;" also "pure, clean; noble, generous" (12c.), from Late Latin mundanus "belonging to the world" (as distinct from the Church), in classical Latin "a citizen of the world, cosmopolite," from mundus "universe, world," literally "clean, elegant"; used as a translation of Greek kosmos (see cosmos) in its Pythagorean sense of "the physical universe" (the original sense of the Greek word was "orderly arrangement"). Latin mundus also was used of a woman's "ornaments, dress," and is related to the adjective mundus "clean, elegant" (used of women's dress, etc.). Related: Mundanely. The mundane era was the chronology that began with the supposed epoch of the Creation (famously reckoned as 4004 B.C.E.).