Maulfaulor mundfaulis an adjective adding faul ("lazy") to Maul ("mouth" of animals) or Mund ("mouth" of people). It literally means "mouth-lazy" and could be translated as "uncommunicative" or "taciturn". But it connotes taciturnity with an attitude, the result of boredom, or an expression of passive resistance. You could call a student who answers a question by a teacher with a shrug "uncommunicative", but maulfaul captures the underlying attitude in a more graphic way, calling up the image of a mouth too lazy to move. That's why I'm fond of the word.