1580s, in Greek mythology a member of the older family of Gods, later regarded as a Titan, son of Iapetus and Clymene; in either case supposed to uphold the pillars of heaven (or earth), which according to one version was his punishment for being the war leader of the Titans in the struggle with the Olympian gods. "Originally the name of an Arcadian mountain god; the name was transferred to the mountain chain in Western Africa" [Beekes].
The Greek name traditionally is interpreted as "The Bearer (of the Heavens)," from a-, copulative prefix (see a- (3)), + stem of tlenai "to bear," from PIE root *tele- "to lift, support, weigh." But Beekes compares Berber adrar "mountain" and finds it plausible that the Greek name is a "folk-etymological reshaping" of this. Mount Atlas, in Mauritania, was important in Greek cosmology as a support of the heavens.
mythical island-nation, by 1730, from Greek Atlantis, literally "daughter of Atlas," noun use of fem. adjective from Atlas (stem Atlant-; see Atlas). All references trace to Plato's dialogues "Timaeus" and "Critias," both written c. 360 B.C.E.