酒精度的定義是指酒中純乙醇(酒精)所含的容量百分比。比如某酒100毫升中純乙醇含量為10毫升，這種酒的酒度就是10度。
英語中可以表達為：Alcohol by volume
wikipedia維基百科
Alcohol by volume (abbreviated as ABV, abv, or alc/vol) is a standard measure of how much alcohol (ethanol) is contained in a given volume of an alcoholic beverage (expressed as a volume percent).
酒精體積(簡寫為ABV、abv或alcvol)是衡量酒精飲料中酒精(乙醇)含量的標準方法(以體積百分比表示)。
It is defined as the number of millilitres (mL) of pure ethanol present in 100 mL (3.4 fl. oz) of solution at 20 °C (68 °F).
它是指在20攝氏度(68華氏度)下，100毫升(3.4盎司)的溶液中所含的純乙醇的毫升數。
The ABV standard is used worldwide.
ABV標準在世界範圍內使用。
例句：
wine at 12% ABV
12度的酒
A：What's the alcohol content of QingDao beer?
青島啤酒的麥芽汁濃度是多少？
（中文裡「啤酒度數」一般指麥芽汁濃度，並不是酒精占比）
B：It's about 7%.
大概百分之七。
alcohol content
（酒精容量）
另外，國外還有另一種常見的計量單位
proof
If you get a bottle of vodka from your local liquor store, you』ll probably see two different numbers telling you how much alcohol it contains. The first is an alcohol by volume (ABV) percentage, which is relatively intuitive to understand: it’s the percentage of alcohol in the overall liquid and is pretty standard internationally.
如果你從當地的酒類商店買了一瓶伏特加，你可能會看到兩個不同的數字告訴你酒里含有多少酒精。第一個是酒精體積百分比(ABV)，這是比較直觀的理解:它是酒精在整個液體中的百分比，在國際上是相當標準的。
The other measurement is proof, a measurement of alcohol content that varies from country to country. The proof measurement harks back to 16th-century England, when the government would put an extra tax on 「proof spirits」—that is, liquor that contained a certain higher amount of alcohol.
還有一種就是酒精濃度，各國的測量方法各不相同。這種酒精含量的測量方式可以追溯到16世紀的英國，當時政府會對達到酒精濃度標準的，即酒精含量較高的烈性酒徵收額外的稅。
A pellet of gunpowder was soaked in spirits. If the pellet burned, the spirits were taxed at a higher rate. The burning was proof of its alcohol content (hence the term 'proof' to measure alcohol content).
方法就是將一粒火藥浸在烈性酒里。如果這粒火藥燃燒了，就證明酒為烈性酒，並將被徵收更高的稅。燃燒是酒精含量的證明(因此有了測量酒精含量的「證明」一詞)。
註：啤酒的度數是指發酵液中麥芽糖的濃度，不是指成品酒中乙醇的含量，而葡萄酒的酒精度主要由葡萄果實中的含糖量決定。所以都和白酒的酒精度數不同。
最後：
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