How did planet earth get it's name?

Answer 1

Lexicography

In American English usage, the name can be capitalized or spelled in lowercase interchangeably, either when used absolutely or prefixed with "the" (i.e. Earth, the Earth, earth or the earth). Many deliberately spell the name of the planet with a capital, both as "Earth" or "the Earth". This is to distinguish it as a proper noun, distinct from the senses of the term as a count noun or verb (e.g. referring to soil, the ground, earthing in the electrical sense, etc.). Oxford Spelling recognizes the lowercase form as the most common, with the capitalized form as a variant of it. Another convention that is very common is to spell the name with a capital when occurring absolutely (e.g. Earth's atmosphere) and lowercase when preceded by "the" (e.g. the atmosphere of the earth). The term almost exclusively exists in lowercase when appearing in common phrases, even without "the" preceding it (e.g. it doesn't cost the earth; what on earth are you doing?).[2]

Terms that refer to the Earth can use the Latin root terr-, as in terraform and terrestrial. An alternative Latin root is tellur-, which is used in words such as tellurian and tellurium. Such terms derive from Latin terra and tellus, which refer variously to the world, the element earth, the earth goddess and so forth[3]. Scientific terms such as geography, geocentric and geothermal use the Greek prefix geo- (γαιο-, gaio-), from gē (again meaning "earth").[4] Astronauts and sailors refer to the Earth as "Terra Firma"[citation needed].

The English word "earth" has cognates in many modern and ancient languages. Examples in modern tongues include aarde in Afrikaans and Dutch, and Erde in German. The root has cognates in extinct languages such as ertha in Old Saxon and ert (meaning "ground") in Middle Irish, derived from the Old English eorðe. All of these words derive from the Proto-Indo-European base *er-.

Several Semitic languages have words for "earth" similar to those in Indo-European languages. Arabic has ard; Akkadian, irtsitu; Aramaic, araa; Phoenician, erets (which appears in the Mesha Stele); and Hebrew, ארץ (arets, or erets when not preceded by a definite article, or when followed by a noun modifier). The etymological connection between the words in Indo-European and Semitic languages are uncertain, though, and may simply be coincidence.

The standard name for people from Earth is Earthling, although Terran, Gaian, and Earther are alternate names that have been used in Science fiction.

Words for Earth in other languages include: Terre (French), पृथ्वी pr̥thvī (Sanskrit), Maa (Finnish and Estonian), Pământ (Romanian), Föld (Hungarian), Ziemia (Polish), Zemlja (Russian and Serbian), Zemya Земя (Bulgarian), Tierra (Spanish), Terra (Italian), Diqiu (Mandarin), Deiqao (Cantonese), Jigu (Korean), Bumi (Malay), Chikyuu (Japanese), Jorden (Danish, Norwegian, Swedish), כדור הארץ (Hebrew), Bhoomi (Telugu), Gi, Choma (Greek), Dunia (Swahili), Âlem, Dünya الْمَسْكُونَة (Arabic), Dinê (Kurdish), Ergir երկիր (Armenian), Jehun, Zamin (Persian), and Acun, Yeryüzü, Yerküre (Turkish).[5]

Answer 2

Earth in Greek is Γη which comes from ancient Γαία which means land.

Answer 3

From the German and Old English for dirt/soil.