The Hittite word ne-e-pi-iš
Word ne-e-pi-iš
IPA nēpiš
Meaning sky, heaven
See also Homeric Greek: νέφος ‘cloud, mass of clouds’
Proto-Indo-European: *nebʰ-o-, nebʰ-i- ‘cloud’
Latin: nebula ‘cloud’

Other words that might be of interest
ua-ar-ša ‘fog, mist’, al-pa-aš ‘cloud’, ar-ma ‘moon’, ḫa-aš-te-er ‘star’