Tra'ka

A thing, concept or quality thought to be so utterly insignificant or beneath contempt that a Dwarf wouldn't think twice before not giving you one. As illustration of the point, Grag Bashfull Bashfullsson assured the Low King that Samuel Vimes did not give a tra'ka for accepted protocol, an observation to which the King of All the Dwarfs, who'd met Vimes before, wearily nodded assent.