A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a left or right bracket or, alternatively, an opening paired bracket or closing paired bracket, respectively, depending on the directionality of the context.

Some of the following names are regional or contextual:

• ( ) – parentheses, brackets (UK, Ireland, Canada, West Indies, New Zealand, South Africa and Australia), parens, round brackets, first brackets, circle brackets or smooth brackets.
• { } – braces (UK and US), curly brackets, definite brackets, swirly brackets, curly braces, birdie brackets, French brackets, Scottish brackets, squirrelly brackets, gullwings, seagulls, squiggly brackets, twirly brackets, Tuborg brackets (DK), accolades (NL), pointy brackets, second brackets, fancy brackets, M Brace, moustache brackets, squiggly parentheses.
• [ ] – brackets (US), square brackets, closed brackets, hard brackets, third brackets, crotchets.
• ⟨ ⟩ – angle brackets, less-than/greater-than signs (when the ASCII approximation of < > is used), pointy brackets, triangular brackets, diamond brackets, tuples, chevrons, guillemets, broken brackets, brokets.[5]
• ⸤ ⸥ ｢ ｣ – corner brackets
• ⟦ ⟧ – double square brackets, white square brackets, Scott brackets
• 〔 〕 – tortoise shell brackets

In English, typographers mostly prefer not to set brackets in italics, even when the enclosed text is italic. However, in other languages like German, if brackets enclose text in italics, they are usually also set in italics.

Parentheses contain adjunctive material that serves to clarify (in the manner of a gloss) or is aside from the main point. A milder effect may be obtained by using a pair of commas as the delimiter, though if the sentence contains commas for other purposes, visual confusion may result. That issue is fixed by using a pair of dashes instead, to bracket the parenthetical.

Parentheses may be used in formal writing to add supplementary information. They can also indicate shorthand for "either singular or plural" for nouns, e.g. "the claim(s)". It can also be used for gender neutral language, especially in languages with grammatical gender, e.g. "(s)he agreed with his/her physician" (the slash in the second instance, as one alternative is replacing the other, not adding to it).

In American usage, parentheses are usually considered separate from other brackets, and calling them "brackets" is unusual.

六级/考研单词: isolate, segment, data, deploy, symmetry, alternate, respective, brace, curl, tentative, tertiary, triangle, diamond, turtle, enclose, clarify, mild, comma, confuse, issue, dash, shorthand, singular, plural, noun, gender, neutral, physician, slash, usage