Collinearity

In geometry, collinearity is a property of a set of points, specifically, the property of lying on a single line. A set of points with this property is said to be collinear (often misspelled as, but should not be confused with, co-linear or colinear). The term collinear has been used, in a generalized sense, both in mathematics and in its application areas, as a synonym for "aligned" or the expression "in a row".