Either or both of the upright curved lines, (or), used to mark off explanatory or qualifying remarks in writing or printing or enclose a sum, product, or other expression considered or treated as a collective entity in a mathematical operation.

• 圆括号，圆括弧两个直立曲线或其中之一，（或），用于标出解释文字及书写或打印中的限定语或包含一个和、积或其它在数学运算中作为或被当作是一个集体的性质的表达式