The correct spelling of the phrase "stat mi" is "statim," pronounced as /ˈstɑːtɪm/ in IPA phonetic transcription. This Latin word means "immediately" or "at once." The confusion in spelling arises from the lack of clear vowels in the original pronunciation of the word. English speakers often insert an "i" in the spelling to show the short "i" sound in the middle. However, the correct spelling still remains as "statim," and the word is widely used in medical and legal settings to denote immediate action.