noun
merrymaking; convivial drinking
Refers to the lively, cheerful atmosphere of a drinking party or banquet. Often used in set phrases like 酒興に乗じて (under the influence of drink).
酒興に乗じて、つい歌ってしまった。
Carried away by the merrymaking, I ended up singing.
宴は酒興のうちに終わった。
The banquet ended in a convivial atmosphere.