你所指的亦可能是拓扑学上的孤点。

孤立点（acnode），在数学上是指坐标满足曲线方程，但并不落在曲线上的点，是一种奇点。

此外，孤立点也可以指是在数据集合中与大多数数据的特征或不一致的数据。

An acnode is an isolated point not on a curve, but whose coordinates satisfy the equation of the curve. The term "isolated point or hermit point" is an equivalent term.

Acnodes are commonly found in the study of algebraic curves over fields which are not algebraically closed, defined as the zero set of a polynomial of two variables. For example the equation