‘括号’ (kuò hào) is a noun meaning ‘parentheses’ — the curved symbols ‘( )’ used in writing and mathematics to enclose supplementary, explanatory, or clarifying information. The first character 括 (kuò) means ‘to enclose’ or ‘to include’, while 号 (hào) means ‘mark’, ‘symbol’, or ‘sign’. Together, they literally convey ‘enclosing symbol’, accurately reflecting the function of parentheses as typographical markers that wrap content. In Chinese, 括号 can refer broadly to any paired delimiters — including round parentheses (圆括号), square brackets (方括号), and curly braces (花括号) — though context usually specifies which type.

This term appears frequently in academic texts, programming documentation, grammar explanations, and mathematical expressions. Unlike English, where ‘parentheses’ is plural by default, 括号 is grammatically singular and uncountable in Chinese; you say 一个括号 pair (e.g., 一个括号表示补充说明), not *两个括号 for a single pair. It’s neutral in register and used equally in formal and informal written contexts.