The word "Semisoun" is a rare and archaic spelling of "sensation". The phonetic transcription of this word in IPA is /sɛnsˈeɪʃən/. The "emi" in "Semisoun" is pronounced as "en" and the "o" is pronounced as "a", which is common in Middle English spelling. The word "sensation" refers to a physical or emotional feeling experienced by a person. While "Semisoun" may not be commonly used nowadays, it serves as a reminder of the evolution of English language over time.