flask  
noun [ C ] uk/flɑːsk/ us/flæsk/
  (HOT DRINKS)      
  UK (US trademark Thermos)保温瓶 
a special container that keeps drinks hot or cold
  a flask of coffee/tea 一保温瓶的咖啡/茶 
   (ALCOHOL)      
  (装于口袋里的)扁酒瓶
a flat bottle that is used to carry alcohol in your pocket
  a hip flask 随身小扁酒瓶 
   (SCIENCE)     
 长颈瓶;烧瓶
a glass container for liquids with a wide base and a narrow neck, used in scientific work