Middle English, from Old English woruld, worold "human secular existence, pursuits, pleasures, and worries of this life," also "a long period of time," also "the human race, mankind, humanity" (but not "the earth"), a word peculiar to Germanic languages, with a literal sense of "age of man."
It is reconstructed to be from a Proto-Germanic compound of *wer "man" (Old English wer, still in werewolf; see virile) and *ald "age" (Old English ald; see old). Cognates include Old Saxon werold, Old Frisian warld, Dutch wereld, Old Norse verold, Old High German weralt, German Welt). Latin saeculum can mean both "age" and "world," as can Greek aiōn.
Originally "life on earth, this world (as opposed to the afterlife)." The sense extended to "the known world," then to "the physical world in the broadest sense, creation, the universe" (by c. 1200).
The oldest sense is in world without end (translating Latin saecula saeculorum), and in worldly. In theology especially "that part of humanity devoted to secular affairs and pleasures of the present state" (mid-14c.), a sense often revived by later sects. In modern scientific conception, "planetary body conceived of as peopled," by 1713.
In Old English gospels, the commonest word for "the physical world," was Middangeard (Old Norse Midgard), literally "the middle enclosure" (see yard (n.1)), which is rooted in Germanic cosmology. Greek kosmos in its ecclesiastical sense of "world of people" sometimes was rendered in Gothic as manaseþs, literally "seed of man." The usual Old Norse word was heimr, literally "abode" (see home).
According to Buck, words for "world" in some other Indo-European languages derive from the root for "bottom, foundation" (such as Irish domun, Old Church Slavonic duno, related to English deep); the Lithuanian word is pasaulis, from pa- "under" + saulė "sun."
The English word later was used of any state or sphere of existence (c. 1200), such as "whole number of people united by a common faith, heritage, etc." (c. 1600). In modern geography, 1550s, "particular portion or part of the globe" (as New World).
It is attested by c., 1200 in emphatic phrases expressing wonder, perplexity, etc. (as how in the world?). The hyperbolic or emphatic meaning "a great quantity or number," in a world of, is from late 14c. For all the world "in every particular" is by mid-14c.
Out of this world "surpassing, marvelous" is from 1928; earlier it meant "dead." To think the world of "hold in highest possible esteem" is by 1886, American English.
I know a little maiden
With hair of raven hue
She thinks the world of me
Though she may not care for you.
["About My Girl," in Bangor (Maine) Commercial, April 3, 1886]
World power in the geopolitical sense is recorded by 1900. World language is by 1867 as "language understood and employed on every continent;" by 1877 in reference to English as the proper one, by 12885 of Volapuk.
World Cup is by 1951; U.S. baseball World Series is by 1893 (originally often World's Series). World-class is attested from 1950, originally of Olympic athletes.
World-wearied is by 1590s.