earth (n.)

Old English eorþe "ground, soil, dirt, dry land; country, district," also used (along with middangeard) for "the (material) world, the abode of man" (as opposed to the heavens or the underworld), from Proto-Germanic *ertho (source also of Old Frisian erthe "earth," Old Saxon ertha, Old Norse jörð, Middle Dutch eerde, Dutch aarde, Old High German erda, German Erde, Gothic airþa), perhaps from an extended form of PIE root *er- (2) "earth, ground." The earth considered as a planet was so called from c. 1400. Use in old chemistry is from 1728. Earth-mover "large digging machine" is from 1940.

earth (v.)

"to commit (a corpse) to earth," late 14c., from earth (n.). Related: Earthed; earthing.


planet (n.)

late Old English planete, from Old French planete (Modern French planète), from Late Latin planeta, from Greek planetes, from (asteres) planetai "wandering (stars)," from planasthai "to wander," a word of uncertain etymology.

Perhaps from a nasalized form of PIE root *pele- (2) "flat; to spread," on the notion of "spread out," "but the semantics are highly problematic," according to Beekes, who notes the similarity of meaning to Greek plazein "to make devious, repel, dissuade from the right path, bewilder," but adds, "it is hard to think of a formal connection."

So called because they have apparent motion, unlike the "fixed" stars. Originally including also the moon and sun; modern scientific sense of "world that orbits a star" is from 1630s. An enlarged form of Greek planes, planetos "who wanders around, wanderer," also "wandering star, planet," in medicine "unstable temperature."



world (n.)

Old English woruld, worold "human existence, the affairs of life," also "a long period of time," also "the human race, mankind, humanity," a word peculiar to Germanic languages (cognates: Old Saxon werold, Old Frisian warld, Dutch wereld, Old Norse verold, Old High German weralt, German Welt), with a literal sense of "age of man," from Proto-Germanic *weraldi-, a compound of *wer "man" (Old English wer, still in werewolf; see virile) + *ald "age" (from PIE root *al- (2) "to grow, nourish").

Originally "life on earth, this world (as opposed to the afterlife)," sense extended to "the known world," then to "the physical world in the broadest sense, the universe" (c. 1200). 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). 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" + saul? "sun."

Original sense in world without end, translating Latin saecula saeculorum, and in worldly. Latin saeculum can mean both "age" and "world," as can Greek ai?n. Meaning "a great quantity or number" is from 1580s. Out of this world "surpassing, marvelous" is from 1928; earlier it meant "dead." World Cup is by 1951; U.S. baseball World Series is by 1893 (originally often World's Series). World power in the geopolitical sense first recorded 1900. World-class is attested from 1950, originally of Olympic athletes.

*pele- (1)

*pel?-, Proto-Indo-European root meaning "to fill," with derivatives referring to abundance and multitude.

*pele- (2)

*pel?-, Proto-Indo-European root meaning "flat; to spread."



There can only be one plane-t. Then you have whats above and whats below.