The correct spelling of the word "interstis" is actually "interstice." The word refers to a small space between things or a gap in a structure. The IPA phonetic transcription of this word is /ɪntərˌstɪs/, which breaks it down into its individual sounds. It begins with the "ih" vowel sound, followed by the "n" and "t" consonant sounds. The second syllable begins with the "er" vowel sound, and ends with the "s" consonant sound. So, when spelling this word, remember to replace the "t" with a "c."