duff       
 adjective mainly UK informal uk/dʌf/ us/dʌf/
 糟糕的;无用的,不中用的;出故障的
bad, not useful, or not working
  He's directed so many movies that you might expect a few duff ones. 他执导了这么多部电影,难免会有几部不成功的作品。 
 duff       
 noun [ C ] uk/dʌf/ us/dʌf/
 US informal臀部,屁股 
a person's bottom
  Get off your duff and start working. 起来开始干活儿了。 
 duff      
verb [ T ] Australian English informal uk/dʌf/ us/dʌf/
 偷走(家畜)后改变其主人的烙印;偷窃(物品)后改变其外观
to steal farm animals by changing the brand (= owner's mark) on them, or to steal goods by changing their appearance
 Phrasal verb   
duff someone up 连续殴打,一阵猛打
to hit someone repeatedly
  Two of the robbers threatened to duff the witness up if he went to the police. 其中有两名劫匪威胁目击者说如果报警就揍他。