What is the meaning of Posset?

A beverage composed of hot milk curdled by some strong infusion, such as wine.

A baby's vomit, comprising curdled milk.

A pudding-like food composed of cream, sugar, and other flavoring, such as lemon.

To curdle; to turn, as milk; to coagulate.

To treat with possets; to pamper.

To vomit up curdled milk.

third-person singular imperfect active subjunctive of possum  "he would be able (to)"

Source: wiktionary.org