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Wiktionary
coplanarity

alt. 1 (context geometry of at least two things, usually lines English) The state or characteristic of being within the same plane. 2 (context astronomy of multiple planets or other orbiting bodies English) The state or characteristic of orbiting a central celestial object within the same orbital plane. n. 1 (context geometry of at least two things, usually lines English) The state or characteristic of being within the same plane. 2 (context astronomy of multiple planets or other orbiting bodies English) The state or characteristic of orbiting a central celestial object within the same orbital plane.

Wikipedia
Coplanarity

In geometry, a set of points in space are coplanar if there exists a geometric plane that contains them all. For example, three points are always coplanar, and if the points are distinct and non-collinear, the plane they determine is unique. However, a set of four or more distinct points will, in general, not lie in a single plane.

Two lines in three-dimensional space are coplanar if there is a plane that includes them both. This occurs if the lines are parallel, or if they intersect each other. Two lines that are not coplanar are called skew lines.

Distance geometry provides a solution technique for the problem of determining whether a set of points is coplanar, knowing only the distances between them.