The spelling of the word "sky in" follows the standard English spelling pattern. The sound "s" is represented by the letter "s," the sound "k" is represented by the letter "k," the sound "ai" is represented by the letter "y," and the sound "n" is represented by the letter "n." In IPA phonetic transcription, the word is spelled /ˈskaɪ ɪn/. This word refers to a phenomenon where the sky appears to be enclosed by the horizon line, often seen during sunset or sunrise.