How was Earth named?

Answer 1

The ground was called blue planet because of the blue color of the oceans.

PS: Afflicted for my English, I speak it and the writing very seldom thus I think that it is not very good.

PSS: I speak and more often writes French than English.

Answer 2

Terms that refer to the Earth can use the Latin root terra-, such as the word terrestrial. There is also the alternative Latin root tellur-, as used in words such as telluric, tellurian, tellurion and Tellurium. Both terms derive from the Roman goddess Terra Mater, who was also called by the presumably more ancient name Tellūs Mater. Scientific terms such as geography, geocentric and geothermal use the Greek prefix geo-, derived from Terra Mater's Greek counterpart Gaia.

The English word "earth" has cognates in many modern and ancient languages. Examples in modern tongues include aarde in Dutch and Erde in German. The root also 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 are derived from the Proto-Indo-European base *er-. Given metathesis, we can find cognates of "earth" between terra and the modern Romance languages, for instance tierra in Spanish or terra in Portuguese.

Answer 3

From a Germanic name for dirt