The correct spelling of the word "stiltest" is actually "stillest". The IPA phonetic transcription for this word is /ˈstɪlɪst/. This word means "most quiet" or "most calm" and is used to describe a person, place, or thing that is very peaceful or serene. The pronunciation of this word is important because it can be easily confused with the word "stilted", which means awkward or stiff. So next time you want to use the word "stillest", remember to spell it correctly!