boxcarred Share definition Flag (prison use) vt, vi, adj: used to describe a prison sentence that runs consecutively to another sentence He got 2 years for assault and 2 more for using a gun, and the judge ran them boxcarred. boxcarred by Lt. Commander Data December 16, 2008 0 0 Get merch Get the boxcarred mug. Buy Now — $32.95 See more merch