The correct spelling of the phrase "wast guest" is actually "waste guest". This term refers to an unwelcome visitor or someone who is not appreciated. The reason for the spelling is due to the silent "e" at the end of the word "waste", which changes the vowel sound from a short "a" to a long "a". The IPA phonetic transcription for "waste" is /weɪst/, which shows the long "a" sound represented by the letter "a" followed by a silent "e".