Earth

== Etymology ==
The [[Modern English]] word {{anchor|Name|Etymology}} ''Earth'' developed, via [[Middle English]], from an [[Old English]] noun most often spelled ''{{linktext|eorðe}}''.<ref name="oedearth">{{cite book|title=Oxford English Dictionary|edition=3|chapter=earth, ''n.¹''|publisher=[[Oxford University Press]]|place=[[Oxford, England|Oxford]], England|year=2010|isbn=978-0-19-957112-3|doi=10.1093/acref/9780199571123.001.0001}}</ref> It has cognates in every [[Germanic languages|Germanic language]], and their [[proto-Germanic|ancestral root]] has been reconstructed as [[wikt:Appendix:Proto-Germanic/erþō|*''erþō'']]. In its earliest attestation, the word ''eorðe'' was used to translate the many senses of [[Latin language|Latin]] ''{{linktext|terra}}'' and [[Ancient Greek language|Greek]] γῆ ''gē'': the ground, its [[soil]], dry land, the human world, the surface of the world (including the sea), and the globe itself. As with Roman [[Terra (goddess)|Terra]]/Tellūs and Greek [[Gaia (goddess)|Gaia]], Earth may have been a [[earth goddess|personified goddess]] in [[Germanic religion (aboriginal)|Germanic paganism]]: late [[Norse mythology]] included [[Jörð]] ("Earth"), a giantess often given as the mother of [[Thor]].<ref>{{cite book|last=Simek|first=Rudolf|author-link=Rudolf Simek|translator-last=Hall|translator-first=Angela|title=Dictionary of Northern Mythology|page=179|publisher=[[Boydell & Brewer|D.S. Brewer]]|year=2007|isbn=978-0-85991-513-7}}</ref>

Historically, "Earth" has been written in lowercase. Beginning with the use of [[Early Middle English]], its [[Definite article|definite sense]] as "the globe" was expressed as "the earth". By the era of [[Early Modern English]], [[Capitalization in English#History of English capitalization|capitalization of nouns began to prevail]], and ''the earth'' was also written ''the Earth'', particularly when referenced along with other heavenly bodies. More recently, the name is sometimes simply given as ''Earth'', by analogy with the names of the [[Solar System|other planets]], though "earth" and forms with "the earth" remain common.<ref name="oedearth" /> [[Style guide|House styles]] now vary: [[Oxford spelling]] recognizes the lowercase form as the more common, with the capitalized form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name, such as a description of the "Earth's atmosphere", but employs the lowercase when it is preceded by "the", such as "the atmosphere of the earth"). It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing?"<ref>{{cite book|title=The New Oxford Dictionary of English|edition=1st|chapter=earth|publisher=Oxford University Press|location=Oxford|year=1998|isbn=978-0-19-861263-6}}</ref>

The name ''Terra'' {{IPAc-en|ˈ|t|ɛr|ə}} occasionally is used in scientific writing and especially in science fiction to distinguish humanity's inhabited planet from others,<ref>{{OED|Terra}}</ref> while in poetry ''Tellus'' {{IPAc-en|ˈ|t|ɛ|l|ə|s}} has been used to denote personification of the Earth.<ref>{{OED|Tellus}}</ref> ''Terra'' is also the name of the planet in some [[Romance languages]], languages that evolved from [[Latin language|Latin]], like Italian and [[Portuguese language|Portuguese]], while in other Romance languages the word gave rise to names with slightly altered spellings, like the [[Spanish language|Spanish]] ''Tierra'' and the [[French language|French]] ''Terre''. The Latinate form ''Gæa'' or ''Gaea'' ({{IPAc-en|lang|'|dʒ|iː|.|ə}}) of the Greek poetic name ''[[Gaia]]'' ({{lang|grc|Γαῖα}}; {{IPA|grc|ɡâi̯.a|lang|link=yes}} or {{IPA-el|ɡâj.ja|}}) is rare, though the alternative spelling ''Gaia'' has become common due to the [[Gaia hypothesis]], in which case its pronunciation is {{IPAc-en|ˈ|g|aɪ|.|ə}} rather than the more classical English {{IPAc-en|ˈ|g|eɪ|.|ə}}.<ref>{{OED|Gaia}}</ref>

There are a number of adjectives for the planet Earth. The word "earthly" is derived from "Earth". From the [[Latin]] ''Terra'' comes ''terran'' {{IPAc-en|ˈ|t|ɛr|ə|n}},<ref>{{OED|Terran}}</ref> ''terrestrial'' {{IPAc-en|t|ə|ˈ|r|ɛ|s|t|r|i|ə|l}},<ref>{{OED|terrestrial}}</ref> and (via French) ''terrene'' {{IPAc-en|t|ə|ˈ|r|iː|n}},<ref>{{OED|terrene}}</ref> and from the Latin ''Tellus'' comes ''tellurian'' {{IPAc-en|t|ɛ|ˈ|l|ʊər|i|ə|n}}<ref>{{OED|tellurian}}</ref> and ''telluric''.<ref>{{Cite encyclopedia |url=http://www.lexico.com/definition/telluric |archive-url=https://web.archive.org/web/20210331100415/https://www.lexico.com/definition/telluric |url-status=dead |archive-date=31 March 2021 |title=telluric |dictionary=[[Lexico]] UK English Dictionary |publisher=[[Oxford University Press]]}}</ref>