duffer1
n.
informal - an incompetent or stupid person.
- Austral./NZ an unproductive mine.
Etymology
C19: from Scots dowfart ‘stupid person’.
duffer2
n.
Austral. informal a person who steals and alters the brands on cattle.
Etymology
C19 (orig. thieves' sl. for ‘someone who sells trashy articles as valuable’): of unknown origin.