Tyrwhitt and Bell print drafty, explained by full of draff or refuse.
draff, draf, n. dregs: the refuse of malt that has been brewed from.
"Guid faith, it's a true sayin, 'The fat sow gets a' the draff,'" rejoined Janet.
This promontory seemed to serve as an appendix for the draff of the neighborhood's rubbish.
They are the draff and offal of a bygone age, and we will not have them obtruded here.
In the result, Wallace's body was tossed over the wall into 'a draff midden,' presumably lifeless.
It may prove "nothing worth, mere chaff and draff much better burnt," but many friends have insisted they found it interesting.