Adieu is a French loanword used as a formal or literary farewell, literally meaning 'to God'; in English it functions as a polite, sometimes ceremonious goodbye. It is often pronounced with a lingering final vowel and a closed, rounded vowel quality, and it can carry a slightly theatrical or archaic tone depending on context. In everyday English, it signals a deliberate, lasting farewell rather than a casual see-you soon.
Full pronunciation guide
