jacket  
noun [ C ] uk/ˈdʒæk.ɪt/ us/ˈdʒæk.ɪt/
  (CLOTHES)      
 A1 短上衣;夹克
a short coat
  a leather/denim/tweed jacket 皮/牛仔布/粗花呢短上衣 
 The keys are in my jacket pocket. 钥匙在我的夹克口袋里。 
 - More examples
 - I felt a bit chilly so I put on a jacket.
 - He draped his jacket over the back of the chair and sat down to eat.
 - He had a neatly folded handkerchief in his jacket pocket.
 - What happened to your jacket? There's a big rip in the sleeve.
 - She was wearing a black leather jacket and shades.
 
  (COVER)        
 护封,书套(同 dust jacket)
→  dust jacket 
  US (UK sleeve)封套,防护罩 
a cover to protect something
  Can you put the record back in its jacket, please? 你能把唱片放回封套里吗?