standard line

noun (1)
variants: or standard route

Definition of standard line

 (Entry 1 of 2)

: a railroad line or route upon which the regular or highest rates apply : a fast-service route in distinction from slower and perhaps longer routes or from one that is partly by rail and partly by water — compare differential route

standard line

noun (2)

Definition of standard line (Entry 2 of 2)

: type casting in which all printed letters and figures regardless of size or style align at the bottom