A business transaction in which one attempts to correct a previous transaction that was catastrophically one-sided. In other words, an attempt to "un-fuck" a completely fucked-up deal. From the Latin "wtfomfg" meaning "Holy fucking shit! What the fuck have I done?!?!?"
After the Herschel Walker trade from the Cowboys to the Vikings (aka "The Great Train Robbery", see Herschel Walker trade on Wikipedia) was made, nothing short of a full reverschel could possibly repair the damage caused by this epically lopsided transaction.