Faerie wine is a drink of faeries that produces great euphoria and disinhibition.
History[]
A Court of Thorns and Roses[]
While in the Spring Court at the Summer Solstice party, Feyre Archeron, to Lucien's frustration, drinks faerie wine which causes her overwhelming happiness and total disinhibition. She just wants to dance the night away with the other faeries.
Later, when Alis is taking her to the cave that leads to Under the Mountain she tells her that while she is there she should not drink the wine as it will not be the same as the Summer Solstice. After she forges her bargain with Rhysand, the High Lord of the Night Court, he makes her drink faerie wine every night and then makes her dance for him in front of others. Although the effect of the wine causes her great disinhibition, it causes her to vomit a lot once the effect has worn off.
Actually, Rhysand gives her the wine to evade reality and take her away for a few moments from the horror of living Under the Mountain.