EARTH (Heb. ’ădhāmâh, ground; ’erets, earth; Gr. gē, earth; oikoumenē, inhabited earth; kosmos, orderly arrangement). The Hebrew word ’ădhāmâh most commonly means the tilled reddish soil of Palestine. But it is also used to denote a piece of real estate (Gen.47.18ff.), earth as a material substance (Gen.2.7), a territory (Gen.28.15), the whole earth (Gen.12.3; Deut.14.2).

Sometimes it is difficult to tell whether the earth or the land is meant, particularly in the prophetic books. For example, in Isa.24.1, Isa.24.3-Isa.24.5, the word “earth” may mean “land” instead. The ancient Hebrew had no idea of the shape or size of the earth, or that it was a planet. The earth was simply the area where men lived, moved, and had their being. But Job.26.7 is a scientifically correct statement, “He spreads out the northern skies over empty space; he suspends the earth over nothing.”

International Standard Bible Encyclopedia (1915)

(’adhamah, ’erets, ’aphar; ge, oikoumene):

In a hilly limestone country like Palestine, the small amount of iron oxide in the rocks tends to be oxidized, and thereby to give a prevailing reddish color to the soil. This is especially the case on relatively barren hills where there is little organic matter present to prevent reddening and give a more blackish tinge.

’Adhamah (compare ’adham, "a man," and Adam) is from ’adham, "to be red," and is used in the senses: "earth" (Ex 20:24), "land" (Ps 105:35), a "land" or country (Isa 14:2), "ground" (Ge 4:11), "the earth" (Ge 7:4).

The word most in use is ’erets, undoubtedly from a most ancient root occurring in many languages, as English "earth," German Erde, Arabic ’ard. It is used in most of the senses of ’adhamah, but less as "soil" and more as "the earth" as a part of the universe; frequently with shamayim, "heavens," as in Ge 1:1: "In the beginning God created the heavens and the earth."

`Aphar and its root word and derivatives are closely paralleled in the Arabic, and refer mainly to "dust" or "dry earth" (compare Arabic `afir, "to be of the color of dust"; `afar "dust"; ya`fur, "a gazelle"; Hebrew `opher, "a gazelle"). Compare Ge 2:7: "Yahweh God formed man of the dust of the ground"; Job 2:12: ".... sprinkled dust upon their heads"; Ps 104:29: ".... they die, and return to their dust"; Ge 18:27: "dust and ashes."

In the Septuagint and New Testament, ge is used in nearly all cases, oikoumene being used a few times for the "habitable earth," as in Lu 21:26 the King James Version.