duff1
  
  n.
 a flour pudding boiled or steamed in a cloth bag.
 
  Etymology
  C19: north. Engl. form of dough.
 
  
    
duff2
  
  adj.
 Brit. informal worthless or false.
n.
 N. Amer. & 
Scottish decaying vegetable matter covering the ground under trees.
 
  Etymology
  C18: of unknown origin.
 
  
    
duff3
  
  v.
 informal   - 
(duff someone up)
 Brit. beat someone up.
 - Austral. steal and alter brands on (cattle).
 - Golf  mishit (a shot).
 
 
  Etymology
  sense 1 (1960s) of uncertain origin; senses 2 and 3 (both C19) prob. back-forms from duffer2 and duffer1 respectively.
 
  
    
duff5
  
  n.
 
(
in phr. up the duff)
 
Brit. informal pregnant.
 
  Etymology
  1940s (orig. Austral.): perh. rel. to duff1.