1) Ad space measure 2) Classified ad measure 
A measure of newspaper advertising space, one column wide and 1/14th inch deep.
[n] - space for one line of print (one column wide and 1/14 inch deep) used to measure advertising
line noun space for one line of print (one column wide and 1/14 inch deep) used to measure advertising
In newspaper classifieds, a measurement denoting 1/4 inch depth by one column width. 14 agate lines = one column inch.
a measure of advertising space, of an inch deep and one column wide.