coot  
noun [ C ] uk/kuːt/ us/kuːt/
  (BIRD)     
  白骨顶(一种生活在水边的黑色小水鸟)
a small, dark bird that lives near rivers and lakes
   (PERSON)      
 US informal(尤指笨的)人,家伙 
an old man who has an unusual or slightly crazy way of behaving 
  Let the old coot sleep - he's not going to help us anyway. 让这个老糊涂虫睡吧——他帮不上我们什么忙了。