Words for sky and heaven in Celtic languages.
| Proto-Celtic | *nemos = sky, heaven |
|---|---|
| Old Irish (Goídelc) | nem [n͈ʲeṽ] = heaven, sky, radiance |
| Irish (Gaeilge) | neamh [nʲavˠ / n̠ʲavˠ / n̠ʲaw] = heaven, sky, firmament neamhaí [n̪ʲial̪ˠ] = heavenly, celestial; droning, monotonous, apathetic |
| Scottish Gaelic (Gàidhlig) | nèamh [n̪ʲɛ̃ːv] = heaven; firmament, the skies nèamhaidh [n̪ʲɛːvɪ] = heavenly, celestial |
| Manx (Gaelg) | niau = heaven niauagh = heavenly, celestial niauoil = divine, heavenly |
| Proto-Brythonic | *neβ̃ [ˈnɛːβ̃] = heaven, sky |
| Old Welsh | nem = heaven |
| Middle Welsh (Kymraec) | new, nym, nef = heaven |
| Welsh (Cymraeg) | nef [neːv] = heaven, paradise; God, providence; sky, firmament nef a daear = heaven and earth |
| Old Cornish | nef = heaven |
| Cornish (Kernewek) | nev = heaven |
| Old Breton | nem = heaven |
| Middle Breton | neff = heaven |
| Breton (Brezhoneg) | neñv [ˈnẽ(w)] = sky, heaven |
Etymology: from the Proto-Indo-European *nébʰos (cloud, mist, moisture) [source].
| Middle Irish (Gaoidhealg) | spéir [ˈsˠkamˠəl̪ˠ] = sky, |
|---|---|
| Irish (Gaeilge) | spéir [spʲeːɾʲ] = sky, air; airiness, brightness, light; sphere, circle, orbit spéirbhean = beautiful woman, fair lady (‘sky-woman’) spéirghealach = ‘sky-brightness’, starry light spéirghlan = clear-skied spéirghorm = sky-blue spéirléas = skylight |
| Scottish Gaelic (Gàidhlig) | speur [sbiər] = the sky, firmament, heavens, heights speur-bhean = beautiful woman (usually in myths) speur glan = clear skies speur-eòlas = star-gazery speur-shiubhal = space travel bàta-speur = airship bun-speura = skyline sgoil-speur = astronomy |
| Manx (Gaelg) | speyr = sky, climate speyr-ghorrym = sky-blue, cerulean speyr-oaylleeaght = aerology speyr voorjeenagh =angry (sky) speyr vreck = mackerel sky corpane speyr(ey) = heavenly body |
| Welsh (Cymraeg) | sffêr [neːv] = sphere, ball, globe, heavely body, sphere (of the sky) |
| Breton (Brezhoneg) | sphère, sfer = sphere, globe |
Etymology from the Latin sphēra / sphaera (ball, globe, sphere), from the Ancient Greek σφαῖρα (sphaîra – ball, globe) [source].
- Another word for sky, and air, in Welsh is awyr [ˈau̯.ɨ̞r / ˈau̯.ɪr], from the Latin āēr (air)
- The Cornish word sky is ebron
- Another word for sky, and heavens, in Breton is oabl [ˈwɑːpl]
Words marked with a * are reconstructions.
Sources: Wiktionary, Am Faclair Beag, Online Manx Dictionary, Teanglann.ie, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Dictionaire Favereau

‘Wybren’ is another not entirely uncommon word for sky in Welsh (it is also the basis of ‘wybrennol’ = celestial.