flask /flɑːsk $ flæsk/ BrE AmE noun [countable]
[ Date: 1300-1400 ; Language: Late Latin ; Origin: flasco ]
1 . British English a special type of bottle that you use to keep liquids either hot or cold, for example when travelling SYN Thermos
2 . a ↑ hip flask
3 . a glass bottle with a narrow top, used in a ↑ laboratory