Plain English Meaning
Official FAA records that list every detail of a published airway: where it starts, where it ends, the points and navigation aids that define it, the headings and distances between those points, and the lowest altitudes you can legally fly on each segment.
Full Definition
FAA documents that capture the technical specifications of published en route airways, including the route's identifier, the navigation aids or fixes that define it, the courses between those points, segment distances, minimum en route altitudes, minimum obstruction clearance altitudes, and changeover points. These records are the source data the FAA uses when it designs, charts, and maintains the airway system.