Sky
Middle English (also in the plural denoting clouds), from Old Norse ský ‘cloud’. The verb dates from the early 19th century.
wiktionary
The noun is derived from Middle English ski, skie, sky(“firmament, heavens, sky; cloud; cloud of mist or vapour; fog, mist; (astrology) certain configuration of the heavens; (astronomy) sphere of the celestial realm; (physiology) cloudiness, smoky residue (for example, in urine)”)[and other forms], [1] from Old Norse ský(“cloud”), from Proto-Germanic *skiwją(“cloud; sky”), from *skiwô(“cloud; cloud cover, haze; sky”) (whence Old English sċēo(“cloud”) and Middle English skew(“air; sky; (rare) cloud”)), from Proto-Indo-European *(s)kewH-(“to cover; to conceal, hide”). [2]
The verb is derived from the noun. [3]
etymonline
sky (n.)
c. 1200, "a cloud," from Old Norse sky "cloud," from Proto-Germanic *skeujam "cloud, cloud cover" (source also of Old English sceo, Old Saxon scio "cloud, region of the clouds, sky;" Old High German scuwo, Old English scua, Old Norse skuggi "shadow;" Gothic skuggwa "mirror"), from PIE root *(s)keu- "to cover, conceal."
Meaning "upper regions of the air" is attested from c. 1300; replaced native heofon in this sense (see heaven). In Middle English, the word can still mean both "cloud" and "heaven," as still in the skies, originally "the clouds." Sky-high is from 1812; phrase the sky's the limit is attested from 1908. Sky-dive first recorded 1965; sky-writing is from 1922.
sky (v.)
"to raise or throw toward the skies," 1802, from sky (n.).
