vinculum

n.联结

a horizontal line drawn over a group of mathematical symbols to indicate that they are to be considered as a single entity or to indicate multiplication, as in x̅, the bar or line is called a vinculum.

名词

1、The vinculum is used to indicate that the group of symbols underneath it should be treated as a single entity in mathematical calculations.
（译文：在数学计算中，vinculum用于表示其下方的符号组应被视为一个整体。）

2、In the equation x̅ = (x1 + x2 + x3)/3, the vinculum is used to indicate that the sum of x1, x2, and x3 should be divided by 3.
（译文：在方程x̅ = (x1 + x2 + x3)/3中，vinculum用于表示x1、x2和x3的和应该被3所除。）