tiszta (égbolt) angolul

hyaline▼noun
[UK: ˈhaɪə.lɪn] [US: ˈhaɪə.lɪn]

unclouded▼◼◼◼adjective
[UK: ˌʌn.ˈklaʊ.dɪd] [US: ˌʌn.ˈklaʊ.dɪd]