cosmo-

c. 1200, "the universe, the world" (but not popular until 1848, when it was taken as the English equivalent to Humboldt's Kosmos in translations from German), from Latinized form of Greek kosmos "order, good order, orderly arrangement," a word with several main senses rooted in those notions: The verb kosmein meant generally "to dispose, prepare," but especially "to order and arrange (troops for battle), to set (an army) in array;" also "to establish (a government or regime);" "to deck, adorn, equip, dress" (especially of women). Thus kosmos had an important secondary sense of "ornaments of a woman's dress, decoration" (compare kosmokomes "dressing the hair," and cosmetic) as well as "the universe, the world."

Pythagoras is said to have been the first to apply this word to "the universe," perhaps originally meaning "the starry firmament," but it later was extended to the whole physical world, including the earth. For specific reference to "the world of people," the classical phrase was he oikoumene (ge) "the inhabited (earth)." Septuagint uses both kosmos and oikoumene. Kosmos also was used in Christian religious writing with a sense of "worldly life, this world (as opposed to the afterlife)," but the more frequent word for this was aiōn, literally "lifetime, age."

The word cosmos often suggested especially "the universe as an embodiment of order and harmony."

late 14c., "description of the universe," from Latin cosmographia; see cosmo- + -graphy. From 1510s as "science which describes and maps the main features of the heavens and earth." Related: Cosmographic; cosmographical; cosmographer.

"a Russian astronaut," 1959, Englishing of Russian kosmonavt, which is ultimately from Greek kosmos (see cosmo-) + nautes "sailor" (from PIE root *nau- "boat"). In reference to space travel, cosmonautic is attested by 1947.