imbecile [n], imbecillic [adj]

• Meaning: a stupid person; a person who is moderate to severe in mental retardation (offensive use)
  
• In Hong Kong slang: 懞仔，死蠢，低能，弱智
  
• In decent Chinese: 愚蠢，笨蛋； 智障 (人士)
  
• Where we first met: New York Times Book Review - 'If the best Lapham can do is to come up with 50 inventive new ways to call Bush an imbecillic oligarch, all he's doing is heckling.' (from review on Pretensions to Empire by Lewis H. Lapham)