The neatline on a map is:
“A border drawn around a map to enclose the legend, scale, title, geographic features, and any other information pertinent to the map, often showing tick marks that indicate intervals of distance. On a standard quadrangle map, the neatlines are the meridians and parallels delimiting the quadrangle.”
The ERSI Press dictionary of GIS terminology / edited by Heather Kennedy. Redlands, Calif. : ERSI Press, c.2001.