or Cuss. Not worth a curse. I don't care a curse (or cuss). Here “curse” is a corruption of cerse or kerse. Similarly, the Latin nihil [nihilum ] is ne hilum, not [worth] the black eye of a bean. Other phrases are “not a straw,” “not a pin,” “not a rap,” “not a dam,” “not a bit,” “not a jot,” “not a pin's point,” “not a button.” (Anglo-Saxon, cerse, cress; German, Kirsche, a cherry.)
“Wisdom and witt nowe is not worthe a kerse.”
Robert Langeland: Piers Ploughman.