longitudo
Longitudo is a Latin noun meaning length or extent, especially the linear dimension of an object along its principal axis. In classical and medieval Latin it is used to denote the distance between endpoints of a straight line or the measure of an object's extent along one dimension. It is closely related to latitudo (breadth or width) and altitudo (height or depth). The term comes from longus “long” with the abstract-noun suffix -tudo.
In geometry and measurement, longitudo appears in descriptions of figures such as segments, lines, or solids
In historical Latin writings longitudo also served to translate the modern concept of length across disciplines,
See also longitudinal, latitudo, altitudo, diameter, radius.