1. （收入、年龄、价格等的）范围，等级段
    If you say that someone or something is in a particular bracket, you mean that they come within a particular range, for example a range of incomes, ages, or prices.

    e.g. ...a 33% top tax rate on everyone in these high-income brackets...
           对所有这些高收入人群征收的33%的最高税率
    e.g. Do you fall outside that age bracket?
           你不属于那个年龄段吗？

2. （固定在墙上的）托架，支架，角撑架
    Brackets are pieces of metal, wood, or plastic that are fastened to a wall in order to support something such as a shelf.

    e.g. Fix the beam with the brackets and screws.
           把横梁用托架和螺丝固定。
    e.g. ...adjustable wall brackets.
           可调节的壁架

3. 把…归为一类；把…相提并论
    If two or more people or things are bracketed together, they are considered to be similar or related in some way.

    e.g. The Magi, Bramins, and Druids were bracketed together as men of wisdom...
           东方三博士、婆罗门和德鲁伊特都被视为富有智慧的人。
    e.g. Austrian wine styles are often bracketed with those of northern Germany.
           人们往往把奥地利葡萄酒的风味与德国北部葡萄酒的风味相提并论。

4. 括号，括弧（美国英语中称作parentheses）
    Brackets are a pair of written marks that you place round a word, expression, or sentence in order to indicate that you are giving extra information. In British English, curved marks like these are also called brackets, but in American English, they are called parentheses .

    e.g. The prices in brackets are special rates for the under 18s...
           括号中的价格是年龄在18岁以下的消费者可以享受的特别优惠价。
    e.g. My annotations appear in square brackets.
           在方括号里有我给的注解。

5. （数学上的）括号
    Brackets are pair of marks that are placed around a series of symbols in a mathematical expression to indicate that those symbols function as one item within the expression.