revelry; wild partying; drinking and singing
A fixed expression evoking a boisterous, carefree atmosphere of drinking and singing. Often used in set phrases like 飲めや歌えの大騒ぎ.
The year-end party was a wild revelry of drinking and singing.
From the imperative forms 飲め (drink!) and 歌え (sing!), linked by the particle や, creating a phrase meaning 'drink and sing!' that became a noun for revelry.