Collinearity indicates that a set of points are on a single straight line. Alternative spellings are co-linear or colinear. The version with the double l is typically preferred due to a latin grammatical rule, an example of which is the spelling of attractive, which derives from ad tractare where the d is lost and the consonant doubled. The fusion of cum linea to produce collinear works in a similar way.
Depending on the technical field it may refer to: