also: のみだい
noun
drinking money; money for drinks
Money set aside or spent on alcoholic drinks, often in a social setting.
今月は飲み代がかさんでしまった。
My drinking expenses piled up this month.
彼は給料の半分を飲み代に使っている。
He spends half his salary on drinking money.
Variant using 呑む, an alternative kanji for 飲む.
Abbreviated spelling without okurigana.
酒代 specifically refers to money spent on sake or alcohol, while 飲み代 can include the cost of the drinking occasion more broadly.
Compound of 飲み (のみ, 'drinking', the continuative form of 飲む) and 代 (しろ, 'cost, charge'). The reading のみだい uses the alternative reading だい for 代.